mirror of https://gitee.com/openkylin/linux.git
2807 lines
63 KiB
C
2807 lines
63 KiB
C
/*
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* Simplified MAC Kernel (smack) security module
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*
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* This file contains the smack hook function implementations.
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*
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* Author:
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* Casey Schaufler <casey@schaufler-ca.com>
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*
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* Copyright (C) 2007 Casey Schaufler <casey@schaufler-ca.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2,
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* as published by the Free Software Foundation.
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*/
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#include <linux/xattr.h>
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#include <linux/pagemap.h>
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#include <linux/mount.h>
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#include <linux/stat.h>
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#include <linux/ext2_fs.h>
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#include <linux/kd.h>
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#include <asm/ioctls.h>
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#include <linux/tcp.h>
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#include <linux/udp.h>
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#include <linux/mutex.h>
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#include <linux/pipe_fs_i.h>
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#include <net/netlabel.h>
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#include <net/cipso_ipv4.h>
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#include <linux/audit.h>
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#include "smack.h"
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#define task_security(task) (task_cred_xxx((task), security))
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/*
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* I hope these are the hokeyist lines of code in the module. Casey.
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*/
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#define DEVPTS_SUPER_MAGIC 0x1cd1
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#define SOCKFS_MAGIC 0x534F434B
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#define TMPFS_MAGIC 0x01021994
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/**
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* smk_fetch - Fetch the smack label from a file.
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* @ip: a pointer to the inode
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* @dp: a pointer to the dentry
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*
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* Returns a pointer to the master list entry for the Smack label
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* or NULL if there was no label to fetch.
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*/
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static char *smk_fetch(struct inode *ip, struct dentry *dp)
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{
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int rc;
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char in[SMK_LABELLEN];
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if (ip->i_op->getxattr == NULL)
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return NULL;
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rc = ip->i_op->getxattr(dp, XATTR_NAME_SMACK, in, SMK_LABELLEN);
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if (rc < 0)
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return NULL;
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return smk_import(in, rc);
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}
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/**
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* new_inode_smack - allocate an inode security blob
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* @smack: a pointer to the Smack label to use in the blob
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*
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* Returns the new blob or NULL if there's no memory available
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*/
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struct inode_smack *new_inode_smack(char *smack)
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{
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struct inode_smack *isp;
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isp = kzalloc(sizeof(struct inode_smack), GFP_KERNEL);
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if (isp == NULL)
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return NULL;
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isp->smk_inode = smack;
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isp->smk_flags = 0;
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mutex_init(&isp->smk_lock);
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return isp;
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}
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/*
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* LSM hooks.
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* We he, that is fun!
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*/
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/**
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* smack_ptrace_may_access - Smack approval on PTRACE_ATTACH
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* @ctp: child task pointer
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*
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* Returns 0 if access is OK, an error code otherwise
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*
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* Do the capability checks, and require read and write.
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*/
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static int smack_ptrace_may_access(struct task_struct *ctp, unsigned int mode)
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{
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int rc;
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rc = cap_ptrace_may_access(ctp, mode);
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if (rc != 0)
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return rc;
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rc = smk_access(current_security(), task_security(ctp), MAY_READWRITE);
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if (rc != 0 && capable(CAP_MAC_OVERRIDE))
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return 0;
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return rc;
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}
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/**
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* smack_ptrace_traceme - Smack approval on PTRACE_TRACEME
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* @ptp: parent task pointer
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*
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* Returns 0 if access is OK, an error code otherwise
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*
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* Do the capability checks, and require read and write.
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*/
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static int smack_ptrace_traceme(struct task_struct *ptp)
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{
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int rc;
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rc = cap_ptrace_traceme(ptp);
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if (rc != 0)
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return rc;
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rc = smk_access(task_security(ptp), current_security(), MAY_READWRITE);
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if (rc != 0 && has_capability(ptp, CAP_MAC_OVERRIDE))
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return 0;
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return rc;
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}
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/**
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* smack_syslog - Smack approval on syslog
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* @type: message type
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*
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* Require that the task has the floor label
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*
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* Returns 0 on success, error code otherwise.
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*/
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static int smack_syslog(int type)
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{
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int rc;
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char *sp = current_security();
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rc = cap_syslog(type);
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if (rc != 0)
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return rc;
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if (capable(CAP_MAC_OVERRIDE))
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return 0;
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if (sp != smack_known_floor.smk_known)
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rc = -EACCES;
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return rc;
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}
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/*
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* Superblock Hooks.
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*/
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/**
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* smack_sb_alloc_security - allocate a superblock blob
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* @sb: the superblock getting the blob
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*
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* Returns 0 on success or -ENOMEM on error.
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*/
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static int smack_sb_alloc_security(struct super_block *sb)
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{
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struct superblock_smack *sbsp;
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sbsp = kzalloc(sizeof(struct superblock_smack), GFP_KERNEL);
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if (sbsp == NULL)
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return -ENOMEM;
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sbsp->smk_root = smack_known_floor.smk_known;
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sbsp->smk_default = smack_known_floor.smk_known;
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sbsp->smk_floor = smack_known_floor.smk_known;
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sbsp->smk_hat = smack_known_hat.smk_known;
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sbsp->smk_initialized = 0;
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spin_lock_init(&sbsp->smk_sblock);
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sb->s_security = sbsp;
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return 0;
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}
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/**
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* smack_sb_free_security - free a superblock blob
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* @sb: the superblock getting the blob
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*
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*/
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static void smack_sb_free_security(struct super_block *sb)
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{
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kfree(sb->s_security);
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sb->s_security = NULL;
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}
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/**
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* smack_sb_copy_data - copy mount options data for processing
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* @type: file system type
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* @orig: where to start
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* @smackopts
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*
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* Returns 0 on success or -ENOMEM on error.
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*
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* Copy the Smack specific mount options out of the mount
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* options list.
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*/
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static int smack_sb_copy_data(char *orig, char *smackopts)
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{
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char *cp, *commap, *otheropts, *dp;
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otheropts = (char *)get_zeroed_page(GFP_KERNEL);
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if (otheropts == NULL)
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return -ENOMEM;
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for (cp = orig, commap = orig; commap != NULL; cp = commap + 1) {
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if (strstr(cp, SMK_FSDEFAULT) == cp)
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dp = smackopts;
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else if (strstr(cp, SMK_FSFLOOR) == cp)
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dp = smackopts;
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else if (strstr(cp, SMK_FSHAT) == cp)
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dp = smackopts;
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else if (strstr(cp, SMK_FSROOT) == cp)
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dp = smackopts;
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else
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dp = otheropts;
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commap = strchr(cp, ',');
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if (commap != NULL)
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*commap = '\0';
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if (*dp != '\0')
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strcat(dp, ",");
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strcat(dp, cp);
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}
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strcpy(orig, otheropts);
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free_page((unsigned long)otheropts);
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return 0;
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}
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/**
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* smack_sb_kern_mount - Smack specific mount processing
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* @sb: the file system superblock
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* @flags: the mount flags
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* @data: the smack mount options
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*
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* Returns 0 on success, an error code on failure
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*/
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static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
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{
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struct dentry *root = sb->s_root;
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struct inode *inode = root->d_inode;
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struct superblock_smack *sp = sb->s_security;
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struct inode_smack *isp;
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char *op;
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char *commap;
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char *nsp;
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spin_lock(&sp->smk_sblock);
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if (sp->smk_initialized != 0) {
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spin_unlock(&sp->smk_sblock);
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return 0;
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}
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sp->smk_initialized = 1;
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spin_unlock(&sp->smk_sblock);
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for (op = data; op != NULL; op = commap) {
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commap = strchr(op, ',');
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if (commap != NULL)
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*commap++ = '\0';
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if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
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op += strlen(SMK_FSHAT);
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nsp = smk_import(op, 0);
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if (nsp != NULL)
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sp->smk_hat = nsp;
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} else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
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op += strlen(SMK_FSFLOOR);
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nsp = smk_import(op, 0);
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if (nsp != NULL)
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sp->smk_floor = nsp;
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} else if (strncmp(op, SMK_FSDEFAULT,
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strlen(SMK_FSDEFAULT)) == 0) {
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op += strlen(SMK_FSDEFAULT);
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nsp = smk_import(op, 0);
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if (nsp != NULL)
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sp->smk_default = nsp;
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} else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
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op += strlen(SMK_FSROOT);
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nsp = smk_import(op, 0);
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if (nsp != NULL)
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sp->smk_root = nsp;
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}
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}
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/*
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* Initialize the root inode.
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*/
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isp = inode->i_security;
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if (isp == NULL)
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inode->i_security = new_inode_smack(sp->smk_root);
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else
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isp->smk_inode = sp->smk_root;
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return 0;
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}
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/**
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* smack_sb_statfs - Smack check on statfs
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* @dentry: identifies the file system in question
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*
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* Returns 0 if current can read the floor of the filesystem,
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* and error code otherwise
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*/
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static int smack_sb_statfs(struct dentry *dentry)
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{
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struct superblock_smack *sbp = dentry->d_sb->s_security;
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return smk_curacc(sbp->smk_floor, MAY_READ);
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}
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/**
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* smack_sb_mount - Smack check for mounting
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* @dev_name: unused
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* @nd: mount point
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* @type: unused
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* @flags: unused
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* @data: unused
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*
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* Returns 0 if current can write the floor of the filesystem
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* being mounted on, an error code otherwise.
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*/
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static int smack_sb_mount(char *dev_name, struct path *path,
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char *type, unsigned long flags, void *data)
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{
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struct superblock_smack *sbp = path->mnt->mnt_sb->s_security;
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return smk_curacc(sbp->smk_floor, MAY_WRITE);
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}
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/**
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* smack_sb_umount - Smack check for unmounting
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* @mnt: file system to unmount
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* @flags: unused
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*
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* Returns 0 if current can write the floor of the filesystem
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* being unmounted, an error code otherwise.
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*/
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static int smack_sb_umount(struct vfsmount *mnt, int flags)
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{
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struct superblock_smack *sbp;
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sbp = mnt->mnt_sb->s_security;
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return smk_curacc(sbp->smk_floor, MAY_WRITE);
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}
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/*
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* Inode hooks
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*/
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/**
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* smack_inode_alloc_security - allocate an inode blob
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* @inode - the inode in need of a blob
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*
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* Returns 0 if it gets a blob, -ENOMEM otherwise
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*/
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static int smack_inode_alloc_security(struct inode *inode)
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{
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inode->i_security = new_inode_smack(current_security());
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if (inode->i_security == NULL)
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return -ENOMEM;
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return 0;
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}
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/**
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* smack_inode_free_security - free an inode blob
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* @inode - the inode with a blob
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*
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* Clears the blob pointer in inode
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*/
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static void smack_inode_free_security(struct inode *inode)
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{
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kfree(inode->i_security);
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inode->i_security = NULL;
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}
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/**
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* smack_inode_init_security - copy out the smack from an inode
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* @inode: the inode
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* @dir: unused
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* @name: where to put the attribute name
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* @value: where to put the attribute value
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* @len: where to put the length of the attribute
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*
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* Returns 0 if it all works out, -ENOMEM if there's no memory
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*/
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static int smack_inode_init_security(struct inode *inode, struct inode *dir,
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char **name, void **value, size_t *len)
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{
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char *isp = smk_of_inode(inode);
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if (name) {
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*name = kstrdup(XATTR_SMACK_SUFFIX, GFP_KERNEL);
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if (*name == NULL)
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return -ENOMEM;
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}
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if (value) {
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*value = kstrdup(isp, GFP_KERNEL);
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if (*value == NULL)
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return -ENOMEM;
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}
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if (len)
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*len = strlen(isp) + 1;
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return 0;
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}
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/**
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* smack_inode_link - Smack check on link
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* @old_dentry: the existing object
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* @dir: unused
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* @new_dentry: the new object
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*
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* Returns 0 if access is permitted, an error code otherwise
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*/
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static int smack_inode_link(struct dentry *old_dentry, struct inode *dir,
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struct dentry *new_dentry)
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{
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int rc;
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char *isp;
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isp = smk_of_inode(old_dentry->d_inode);
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rc = smk_curacc(isp, MAY_WRITE);
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if (rc == 0 && new_dentry->d_inode != NULL) {
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isp = smk_of_inode(new_dentry->d_inode);
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rc = smk_curacc(isp, MAY_WRITE);
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}
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return rc;
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}
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/**
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* smack_inode_unlink - Smack check on inode deletion
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* @dir: containing directory object
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* @dentry: file to unlink
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*
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* Returns 0 if current can write the containing directory
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* and the object, error code otherwise
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*/
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static int smack_inode_unlink(struct inode *dir, struct dentry *dentry)
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{
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struct inode *ip = dentry->d_inode;
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int rc;
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/*
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* You need write access to the thing you're unlinking
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*/
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rc = smk_curacc(smk_of_inode(ip), MAY_WRITE);
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if (rc == 0)
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/*
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* You also need write access to the containing directory
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*/
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rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
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return rc;
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}
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/**
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* smack_inode_rmdir - Smack check on directory deletion
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* @dir: containing directory object
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* @dentry: directory to unlink
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*
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* Returns 0 if current can write the containing directory
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* and the directory, error code otherwise
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*/
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static int smack_inode_rmdir(struct inode *dir, struct dentry *dentry)
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{
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int rc;
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/*
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* You need write access to the thing you're removing
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*/
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rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
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if (rc == 0)
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/*
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* You also need write access to the containing directory
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*/
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rc = smk_curacc(smk_of_inode(dir), MAY_WRITE);
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return rc;
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}
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/**
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* smack_inode_rename - Smack check on rename
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* @old_inode: the old directory
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* @old_dentry: unused
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* @new_inode: the new directory
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* @new_dentry: unused
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*
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* Read and write access is required on both the old and
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* new directories.
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*
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* Returns 0 if access is permitted, an error code otherwise
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*/
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static int smack_inode_rename(struct inode *old_inode,
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struct dentry *old_dentry,
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struct inode *new_inode,
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struct dentry *new_dentry)
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{
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int rc;
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char *isp;
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isp = smk_of_inode(old_dentry->d_inode);
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rc = smk_curacc(isp, MAY_READWRITE);
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if (rc == 0 && new_dentry->d_inode != NULL) {
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isp = smk_of_inode(new_dentry->d_inode);
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rc = smk_curacc(isp, MAY_READWRITE);
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}
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return rc;
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}
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/**
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* smack_inode_permission - Smack version of permission()
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* @inode: the inode in question
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* @mask: the access requested
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* @nd: unused
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*
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* This is the important Smack hook.
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*
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* Returns 0 if access is permitted, -EACCES otherwise
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*/
|
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static int smack_inode_permission(struct inode *inode, int mask)
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{
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/*
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|
* No permission to check. Existence test. Yup, it's there.
|
|
*/
|
|
if (mask == 0)
|
|
return 0;
|
|
|
|
return smk_curacc(smk_of_inode(inode), mask);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_setattr - Smack check for setting attributes
|
|
* @dentry: the object
|
|
* @iattr: for the force flag
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_setattr(struct dentry *dentry, struct iattr *iattr)
|
|
{
|
|
/*
|
|
* Need to allow for clearing the setuid bit.
|
|
*/
|
|
if (iattr->ia_valid & ATTR_FORCE)
|
|
return 0;
|
|
|
|
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_getattr - Smack check for getting attributes
|
|
* @mnt: unused
|
|
* @dentry: the object
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
|
|
{
|
|
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
|
|
}
|
|
|
|
/**
|
|
* smack_inode_setxattr - Smack check for setting xattrs
|
|
* @dentry: the object
|
|
* @name: name of the attribute
|
|
* @value: unused
|
|
* @size: unused
|
|
* @flags: unused
|
|
*
|
|
* This protects the Smack attribute explicitly.
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_setxattr(struct dentry *dentry, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
int rc = 0;
|
|
|
|
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
|
|
if (!capable(CAP_MAC_ADMIN))
|
|
rc = -EPERM;
|
|
} else
|
|
rc = cap_inode_setxattr(dentry, name, value, size, flags);
|
|
|
|
if (rc == 0)
|
|
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_post_setxattr - Apply the Smack update approved above
|
|
* @dentry: object
|
|
* @name: attribute name
|
|
* @value: attribute value
|
|
* @size: attribute size
|
|
* @flags: unused
|
|
*
|
|
* Set the pointer in the inode blob to the entry found
|
|
* in the master label list.
|
|
*/
|
|
static void smack_inode_post_setxattr(struct dentry *dentry, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
struct inode_smack *isp;
|
|
char *nsp;
|
|
|
|
/*
|
|
* Not SMACK
|
|
*/
|
|
if (strcmp(name, XATTR_NAME_SMACK))
|
|
return;
|
|
|
|
if (size >= SMK_LABELLEN)
|
|
return;
|
|
|
|
isp = dentry->d_inode->i_security;
|
|
|
|
/*
|
|
* No locking is done here. This is a pointer
|
|
* assignment.
|
|
*/
|
|
nsp = smk_import(value, size);
|
|
if (nsp != NULL)
|
|
isp->smk_inode = nsp;
|
|
else
|
|
isp->smk_inode = smack_known_invalid.smk_known;
|
|
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* smack_inode_getxattr - Smack check on getxattr
|
|
* @dentry: the object
|
|
* @name: unused
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_getxattr(struct dentry *dentry, const char *name)
|
|
{
|
|
return smk_curacc(smk_of_inode(dentry->d_inode), MAY_READ);
|
|
}
|
|
|
|
/*
|
|
* smack_inode_removexattr - Smack check on removexattr
|
|
* @dentry: the object
|
|
* @name: name of the attribute
|
|
*
|
|
* Removing the Smack attribute requires CAP_MAC_ADMIN
|
|
*
|
|
* Returns 0 if access is permitted, an error code otherwise
|
|
*/
|
|
static int smack_inode_removexattr(struct dentry *dentry, const char *name)
|
|
{
|
|
int rc = 0;
|
|
|
|
if (strcmp(name, XATTR_NAME_SMACK) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPIN) == 0 ||
|
|
strcmp(name, XATTR_NAME_SMACKIPOUT) == 0) {
|
|
if (!capable(CAP_MAC_ADMIN))
|
|
rc = -EPERM;
|
|
} else
|
|
rc = cap_inode_removexattr(dentry, name);
|
|
|
|
if (rc == 0)
|
|
rc = smk_curacc(smk_of_inode(dentry->d_inode), MAY_WRITE);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_getsecurity - get smack xattrs
|
|
* @inode: the object
|
|
* @name: attribute name
|
|
* @buffer: where to put the result
|
|
* @size: size of the buffer
|
|
* @err: unused
|
|
*
|
|
* Returns the size of the attribute or an error code
|
|
*/
|
|
static int smack_inode_getsecurity(const struct inode *inode,
|
|
const char *name, void **buffer,
|
|
bool alloc)
|
|
{
|
|
struct socket_smack *ssp;
|
|
struct socket *sock;
|
|
struct super_block *sbp;
|
|
struct inode *ip = (struct inode *)inode;
|
|
char *isp;
|
|
int ilen;
|
|
int rc = 0;
|
|
|
|
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
|
|
isp = smk_of_inode(inode);
|
|
ilen = strlen(isp) + 1;
|
|
*buffer = isp;
|
|
return ilen;
|
|
}
|
|
|
|
/*
|
|
* The rest of the Smack xattrs are only on sockets.
|
|
*/
|
|
sbp = ip->i_sb;
|
|
if (sbp->s_magic != SOCKFS_MAGIC)
|
|
return -EOPNOTSUPP;
|
|
|
|
sock = SOCKET_I(ip);
|
|
if (sock == NULL || sock->sk == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
ssp = sock->sk->sk_security;
|
|
|
|
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
|
|
isp = ssp->smk_in;
|
|
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0)
|
|
isp = ssp->smk_out;
|
|
else
|
|
return -EOPNOTSUPP;
|
|
|
|
ilen = strlen(isp) + 1;
|
|
if (rc == 0) {
|
|
*buffer = isp;
|
|
rc = ilen;
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
/**
|
|
* smack_inode_listsecurity - list the Smack attributes
|
|
* @inode: the object
|
|
* @buffer: where they go
|
|
* @buffer_size: size of buffer
|
|
*
|
|
* Returns 0 on success, -EINVAL otherwise
|
|
*/
|
|
static int smack_inode_listsecurity(struct inode *inode, char *buffer,
|
|
size_t buffer_size)
|
|
{
|
|
int len = strlen(XATTR_NAME_SMACK);
|
|
|
|
if (buffer != NULL && len <= buffer_size) {
|
|
memcpy(buffer, XATTR_NAME_SMACK, len);
|
|
return len;
|
|
}
|
|
return -EINVAL;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_getsecid - Extract inode's security id
|
|
* @inode: inode to extract the info from
|
|
* @secid: where result will be saved
|
|
*/
|
|
static void smack_inode_getsecid(const struct inode *inode, u32 *secid)
|
|
{
|
|
struct inode_smack *isp = inode->i_security;
|
|
|
|
*secid = smack_to_secid(isp->smk_inode);
|
|
}
|
|
|
|
/*
|
|
* File Hooks
|
|
*/
|
|
|
|
/**
|
|
* smack_file_permission - Smack check on file operations
|
|
* @file: unused
|
|
* @mask: unused
|
|
*
|
|
* Returns 0
|
|
*
|
|
* Should access checks be done on each read or write?
|
|
* UNICOS and SELinux say yes.
|
|
* Trusted Solaris, Trusted Irix, and just about everyone else says no.
|
|
*
|
|
* I'll say no for now. Smack does not do the frequent
|
|
* label changing that SELinux does.
|
|
*/
|
|
static int smack_file_permission(struct file *file, int mask)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_file_alloc_security - assign a file security blob
|
|
* @file: the object
|
|
*
|
|
* The security blob for a file is a pointer to the master
|
|
* label list, so no allocation is done.
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_file_alloc_security(struct file *file)
|
|
{
|
|
file->f_security = current_security();
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_file_free_security - clear a file security blob
|
|
* @file: the object
|
|
*
|
|
* The security blob for a file is a pointer to the master
|
|
* label list, so no memory is freed.
|
|
*/
|
|
static void smack_file_free_security(struct file *file)
|
|
{
|
|
file->f_security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_file_ioctl - Smack check on ioctls
|
|
* @file: the object
|
|
* @cmd: what to do
|
|
* @arg: unused
|
|
*
|
|
* Relies heavily on the correct use of the ioctl command conventions.
|
|
*
|
|
* Returns 0 if allowed, error code otherwise
|
|
*/
|
|
static int smack_file_ioctl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int rc = 0;
|
|
|
|
if (_IOC_DIR(cmd) & _IOC_WRITE)
|
|
rc = smk_curacc(file->f_security, MAY_WRITE);
|
|
|
|
if (rc == 0 && (_IOC_DIR(cmd) & _IOC_READ))
|
|
rc = smk_curacc(file->f_security, MAY_READ);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_file_lock - Smack check on file locking
|
|
* @file: the object
|
|
* @cmd unused
|
|
*
|
|
* Returns 0 if current has write access, error code otherwise
|
|
*/
|
|
static int smack_file_lock(struct file *file, unsigned int cmd)
|
|
{
|
|
return smk_curacc(file->f_security, MAY_WRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_file_fcntl - Smack check on fcntl
|
|
* @file: the object
|
|
* @cmd: what action to check
|
|
* @arg: unused
|
|
*
|
|
* Returns 0 if current has access, error code otherwise
|
|
*/
|
|
static int smack_file_fcntl(struct file *file, unsigned int cmd,
|
|
unsigned long arg)
|
|
{
|
|
int rc;
|
|
|
|
switch (cmd) {
|
|
case F_DUPFD:
|
|
case F_GETFD:
|
|
case F_GETFL:
|
|
case F_GETLK:
|
|
case F_GETOWN:
|
|
case F_GETSIG:
|
|
rc = smk_curacc(file->f_security, MAY_READ);
|
|
break;
|
|
case F_SETFD:
|
|
case F_SETFL:
|
|
case F_SETLK:
|
|
case F_SETLKW:
|
|
case F_SETOWN:
|
|
case F_SETSIG:
|
|
rc = smk_curacc(file->f_security, MAY_WRITE);
|
|
break;
|
|
default:
|
|
rc = smk_curacc(file->f_security, MAY_READWRITE);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_file_set_fowner - set the file security blob value
|
|
* @file: object in question
|
|
*
|
|
* Returns 0
|
|
* Further research may be required on this one.
|
|
*/
|
|
static int smack_file_set_fowner(struct file *file)
|
|
{
|
|
file->f_security = current_security();
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_file_send_sigiotask - Smack on sigio
|
|
* @tsk: The target task
|
|
* @fown: the object the signal come from
|
|
* @signum: unused
|
|
*
|
|
* Allow a privileged task to get signals even if it shouldn't
|
|
*
|
|
* Returns 0 if a subject with the object's smack could
|
|
* write to the task, an error code otherwise.
|
|
*/
|
|
static int smack_file_send_sigiotask(struct task_struct *tsk,
|
|
struct fown_struct *fown, int signum)
|
|
{
|
|
struct file *file;
|
|
int rc;
|
|
|
|
/*
|
|
* struct fown_struct is never outside the context of a struct file
|
|
*/
|
|
file = container_of(fown, struct file, f_owner);
|
|
rc = smk_access(file->f_security, tsk->cred->security, MAY_WRITE);
|
|
if (rc != 0 && has_capability(tsk, CAP_MAC_OVERRIDE))
|
|
return 0;
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_file_receive - Smack file receive check
|
|
* @file: the object
|
|
*
|
|
* Returns 0 if current has access, error code otherwise
|
|
*/
|
|
static int smack_file_receive(struct file *file)
|
|
{
|
|
int may = 0;
|
|
|
|
/*
|
|
* This code relies on bitmasks.
|
|
*/
|
|
if (file->f_mode & FMODE_READ)
|
|
may = MAY_READ;
|
|
if (file->f_mode & FMODE_WRITE)
|
|
may |= MAY_WRITE;
|
|
|
|
return smk_curacc(file->f_security, may);
|
|
}
|
|
|
|
/*
|
|
* Task hooks
|
|
*/
|
|
|
|
/**
|
|
* smack_cred_free - "free" task-level security credentials
|
|
* @cred: the credentials in question
|
|
*
|
|
* Smack isn't using copies of blobs. Everyone
|
|
* points to an immutable list. The blobs never go away.
|
|
* There is no leak here.
|
|
*/
|
|
static void smack_cred_free(struct cred *cred)
|
|
{
|
|
cred->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_cred_prepare - prepare new set of credentials for modification
|
|
* @new: the new credentials
|
|
* @old: the original credentials
|
|
* @gfp: the atomicity of any memory allocations
|
|
*
|
|
* Prepare a new set of credentials for modification.
|
|
*/
|
|
static int smack_cred_prepare(struct cred *new, const struct cred *old,
|
|
gfp_t gfp)
|
|
{
|
|
new->security = old->security;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* commit new credentials
|
|
* @new: the new credentials
|
|
* @old: the original credentials
|
|
*/
|
|
static void smack_cred_commit(struct cred *new, const struct cred *old)
|
|
{
|
|
}
|
|
|
|
/**
|
|
* smack_kernel_act_as - Set the subjective context in a set of credentials
|
|
* @new points to the set of credentials to be modified.
|
|
* @secid specifies the security ID to be set
|
|
*
|
|
* Set the security data for a kernel service.
|
|
*/
|
|
static int smack_kernel_act_as(struct cred *new, u32 secid)
|
|
{
|
|
char *smack = smack_from_secid(secid);
|
|
|
|
if (smack == NULL)
|
|
return -EINVAL;
|
|
|
|
new->security = smack;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_kernel_create_files_as - Set the file creation label in a set of creds
|
|
* @new points to the set of credentials to be modified
|
|
* @inode points to the inode to use as a reference
|
|
*
|
|
* Set the file creation context in a set of credentials to the same
|
|
* as the objective context of the specified inode
|
|
*/
|
|
static int smack_kernel_create_files_as(struct cred *new,
|
|
struct inode *inode)
|
|
{
|
|
struct inode_smack *isp = inode->i_security;
|
|
|
|
new->security = isp->smk_inode;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_task_setpgid - Smack check on setting pgid
|
|
* @p: the task object
|
|
* @pgid: unused
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_setpgid(struct task_struct *p, pid_t pgid)
|
|
{
|
|
return smk_curacc(task_security(p), MAY_WRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_task_getpgid - Smack access check for getpgid
|
|
* @p: the object task
|
|
*
|
|
* Returns 0 if current can read the object task, error code otherwise
|
|
*/
|
|
static int smack_task_getpgid(struct task_struct *p)
|
|
{
|
|
return smk_curacc(task_security(p), MAY_READ);
|
|
}
|
|
|
|
/**
|
|
* smack_task_getsid - Smack access check for getsid
|
|
* @p: the object task
|
|
*
|
|
* Returns 0 if current can read the object task, error code otherwise
|
|
*/
|
|
static int smack_task_getsid(struct task_struct *p)
|
|
{
|
|
return smk_curacc(task_security(p), MAY_READ);
|
|
}
|
|
|
|
/**
|
|
* smack_task_getsecid - get the secid of the task
|
|
* @p: the object task
|
|
* @secid: where to put the result
|
|
*
|
|
* Sets the secid to contain a u32 version of the smack label.
|
|
*/
|
|
static void smack_task_getsecid(struct task_struct *p, u32 *secid)
|
|
{
|
|
*secid = smack_to_secid(task_security(p));
|
|
}
|
|
|
|
/**
|
|
* smack_task_setnice - Smack check on setting nice
|
|
* @p: the task object
|
|
* @nice: unused
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_setnice(struct task_struct *p, int nice)
|
|
{
|
|
int rc;
|
|
|
|
rc = cap_task_setnice(p, nice);
|
|
if (rc == 0)
|
|
rc = smk_curacc(task_security(p), MAY_WRITE);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_task_setioprio - Smack check on setting ioprio
|
|
* @p: the task object
|
|
* @ioprio: unused
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_setioprio(struct task_struct *p, int ioprio)
|
|
{
|
|
int rc;
|
|
|
|
rc = cap_task_setioprio(p, ioprio);
|
|
if (rc == 0)
|
|
rc = smk_curacc(task_security(p), MAY_WRITE);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_task_getioprio - Smack check on reading ioprio
|
|
* @p: the task object
|
|
*
|
|
* Return 0 if read access is permitted
|
|
*/
|
|
static int smack_task_getioprio(struct task_struct *p)
|
|
{
|
|
return smk_curacc(task_security(p), MAY_READ);
|
|
}
|
|
|
|
/**
|
|
* smack_task_setscheduler - Smack check on setting scheduler
|
|
* @p: the task object
|
|
* @policy: unused
|
|
* @lp: unused
|
|
*
|
|
* Return 0 if read access is permitted
|
|
*/
|
|
static int smack_task_setscheduler(struct task_struct *p, int policy,
|
|
struct sched_param *lp)
|
|
{
|
|
int rc;
|
|
|
|
rc = cap_task_setscheduler(p, policy, lp);
|
|
if (rc == 0)
|
|
rc = smk_curacc(task_security(p), MAY_WRITE);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_task_getscheduler - Smack check on reading scheduler
|
|
* @p: the task object
|
|
*
|
|
* Return 0 if read access is permitted
|
|
*/
|
|
static int smack_task_getscheduler(struct task_struct *p)
|
|
{
|
|
return smk_curacc(task_security(p), MAY_READ);
|
|
}
|
|
|
|
/**
|
|
* smack_task_movememory - Smack check on moving memory
|
|
* @p: the task object
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*/
|
|
static int smack_task_movememory(struct task_struct *p)
|
|
{
|
|
return smk_curacc(task_security(p), MAY_WRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_task_kill - Smack check on signal delivery
|
|
* @p: the task object
|
|
* @info: unused
|
|
* @sig: unused
|
|
* @secid: identifies the smack to use in lieu of current's
|
|
*
|
|
* Return 0 if write access is permitted
|
|
*
|
|
* The secid behavior is an artifact of an SELinux hack
|
|
* in the USB code. Someday it may go away.
|
|
*/
|
|
static int smack_task_kill(struct task_struct *p, struct siginfo *info,
|
|
int sig, u32 secid)
|
|
{
|
|
/*
|
|
* Sending a signal requires that the sender
|
|
* can write the receiver.
|
|
*/
|
|
if (secid == 0)
|
|
return smk_curacc(task_security(p), MAY_WRITE);
|
|
/*
|
|
* If the secid isn't 0 we're dealing with some USB IO
|
|
* specific behavior. This is not clean. For one thing
|
|
* we can't take privilege into account.
|
|
*/
|
|
return smk_access(smack_from_secid(secid), task_security(p), MAY_WRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_task_wait - Smack access check for waiting
|
|
* @p: task to wait for
|
|
*
|
|
* Returns 0 if current can wait for p, error code otherwise
|
|
*/
|
|
static int smack_task_wait(struct task_struct *p)
|
|
{
|
|
int rc;
|
|
|
|
rc = smk_access(current_security(), task_security(p), MAY_WRITE);
|
|
if (rc == 0)
|
|
return 0;
|
|
|
|
/*
|
|
* Allow the operation to succeed if either task
|
|
* has privilege to perform operations that might
|
|
* account for the smack labels having gotten to
|
|
* be different in the first place.
|
|
*
|
|
* This breaks the strict subject/object access
|
|
* control ideal, taking the object's privilege
|
|
* state into account in the decision as well as
|
|
* the smack value.
|
|
*/
|
|
if (capable(CAP_MAC_OVERRIDE) || has_capability(p, CAP_MAC_OVERRIDE))
|
|
return 0;
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_task_to_inode - copy task smack into the inode blob
|
|
* @p: task to copy from
|
|
* inode: inode to copy to
|
|
*
|
|
* Sets the smack pointer in the inode security blob
|
|
*/
|
|
static void smack_task_to_inode(struct task_struct *p, struct inode *inode)
|
|
{
|
|
struct inode_smack *isp = inode->i_security;
|
|
isp->smk_inode = task_security(p);
|
|
}
|
|
|
|
/*
|
|
* Socket hooks.
|
|
*/
|
|
|
|
/**
|
|
* smack_sk_alloc_security - Allocate a socket blob
|
|
* @sk: the socket
|
|
* @family: unused
|
|
* @priority: memory allocation priority
|
|
*
|
|
* Assign Smack pointers to current
|
|
*
|
|
* Returns 0 on success, -ENOMEM is there's no memory
|
|
*/
|
|
static int smack_sk_alloc_security(struct sock *sk, int family, gfp_t gfp_flags)
|
|
{
|
|
char *csp = current_security();
|
|
struct socket_smack *ssp;
|
|
|
|
ssp = kzalloc(sizeof(struct socket_smack), gfp_flags);
|
|
if (ssp == NULL)
|
|
return -ENOMEM;
|
|
|
|
ssp->smk_in = csp;
|
|
ssp->smk_out = csp;
|
|
ssp->smk_packet[0] = '\0';
|
|
|
|
sk->sk_security = ssp;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_sk_free_security - Free a socket blob
|
|
* @sk: the socket
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_sk_free_security(struct sock *sk)
|
|
{
|
|
kfree(sk->sk_security);
|
|
}
|
|
|
|
/**
|
|
* smack_set_catset - convert a capset to netlabel mls categories
|
|
* @catset: the Smack categories
|
|
* @sap: where to put the netlabel categories
|
|
*
|
|
* Allocates and fills attr.mls.cat
|
|
*/
|
|
static void smack_set_catset(char *catset, struct netlbl_lsm_secattr *sap)
|
|
{
|
|
unsigned char *cp;
|
|
unsigned char m;
|
|
int cat;
|
|
int rc;
|
|
int byte;
|
|
|
|
if (!catset)
|
|
return;
|
|
|
|
sap->flags |= NETLBL_SECATTR_MLS_CAT;
|
|
sap->attr.mls.cat = netlbl_secattr_catmap_alloc(GFP_ATOMIC);
|
|
sap->attr.mls.cat->startbit = 0;
|
|
|
|
for (cat = 1, cp = catset, byte = 0; byte < SMK_LABELLEN; cp++, byte++)
|
|
for (m = 0x80; m != 0; m >>= 1, cat++) {
|
|
if ((m & *cp) == 0)
|
|
continue;
|
|
rc = netlbl_secattr_catmap_setbit(sap->attr.mls.cat,
|
|
cat, GFP_ATOMIC);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* smack_to_secattr - fill a secattr from a smack value
|
|
* @smack: the smack value
|
|
* @nlsp: where the result goes
|
|
*
|
|
* Casey says that CIPSO is good enough for now.
|
|
* It can be used to effect.
|
|
* It can also be abused to effect when necessary.
|
|
* Appologies to the TSIG group in general and GW in particular.
|
|
*/
|
|
static void smack_to_secattr(char *smack, struct netlbl_lsm_secattr *nlsp)
|
|
{
|
|
struct smack_cipso cipso;
|
|
int rc;
|
|
|
|
switch (smack_net_nltype) {
|
|
case NETLBL_NLTYPE_CIPSOV4:
|
|
nlsp->domain = smack;
|
|
nlsp->flags = NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
|
|
|
|
rc = smack_to_cipso(smack, &cipso);
|
|
if (rc == 0) {
|
|
nlsp->attr.mls.lvl = cipso.smk_level;
|
|
smack_set_catset(cipso.smk_catset, nlsp);
|
|
} else {
|
|
nlsp->attr.mls.lvl = smack_cipso_direct;
|
|
smack_set_catset(smack, nlsp);
|
|
}
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* smack_netlabel - Set the secattr on a socket
|
|
* @sk: the socket
|
|
*
|
|
* Convert the outbound smack value (smk_out) to a
|
|
* secattr and attach it to the socket.
|
|
*
|
|
* Returns 0 on success or an error code
|
|
*/
|
|
static int smack_netlabel(struct sock *sk)
|
|
{
|
|
struct socket_smack *ssp;
|
|
struct netlbl_lsm_secattr secattr;
|
|
int rc;
|
|
|
|
ssp = sk->sk_security;
|
|
netlbl_secattr_init(&secattr);
|
|
smack_to_secattr(ssp->smk_out, &secattr);
|
|
rc = netlbl_sock_setattr(sk, &secattr);
|
|
netlbl_secattr_destroy(&secattr);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_inode_setsecurity - set smack xattrs
|
|
* @inode: the object
|
|
* @name: attribute name
|
|
* @value: attribute value
|
|
* @size: size of the attribute
|
|
* @flags: unused
|
|
*
|
|
* Sets the named attribute in the appropriate blob
|
|
*
|
|
* Returns 0 on success, or an error code
|
|
*/
|
|
static int smack_inode_setsecurity(struct inode *inode, const char *name,
|
|
const void *value, size_t size, int flags)
|
|
{
|
|
char *sp;
|
|
struct inode_smack *nsp = inode->i_security;
|
|
struct socket_smack *ssp;
|
|
struct socket *sock;
|
|
int rc = 0;
|
|
|
|
if (value == NULL || size > SMK_LABELLEN)
|
|
return -EACCES;
|
|
|
|
sp = smk_import(value, size);
|
|
if (sp == NULL)
|
|
return -EINVAL;
|
|
|
|
if (strcmp(name, XATTR_SMACK_SUFFIX) == 0) {
|
|
nsp->smk_inode = sp;
|
|
return 0;
|
|
}
|
|
/*
|
|
* The rest of the Smack xattrs are only on sockets.
|
|
*/
|
|
if (inode->i_sb->s_magic != SOCKFS_MAGIC)
|
|
return -EOPNOTSUPP;
|
|
|
|
sock = SOCKET_I(inode);
|
|
if (sock == NULL || sock->sk == NULL)
|
|
return -EOPNOTSUPP;
|
|
|
|
ssp = sock->sk->sk_security;
|
|
|
|
if (strcmp(name, XATTR_SMACK_IPIN) == 0)
|
|
ssp->smk_in = sp;
|
|
else if (strcmp(name, XATTR_SMACK_IPOUT) == 0) {
|
|
ssp->smk_out = sp;
|
|
rc = smack_netlabel(sock->sk);
|
|
if (rc != 0)
|
|
printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
|
|
__func__, -rc);
|
|
} else
|
|
return -EOPNOTSUPP;
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_socket_post_create - finish socket setup
|
|
* @sock: the socket
|
|
* @family: protocol family
|
|
* @type: unused
|
|
* @protocol: unused
|
|
* @kern: unused
|
|
*
|
|
* Sets the netlabel information on the socket
|
|
*
|
|
* Returns 0 on success, and error code otherwise
|
|
*/
|
|
static int smack_socket_post_create(struct socket *sock, int family,
|
|
int type, int protocol, int kern)
|
|
{
|
|
if (family != PF_INET || sock->sk == NULL)
|
|
return 0;
|
|
/*
|
|
* Set the outbound netlbl.
|
|
*/
|
|
return smack_netlabel(sock->sk);
|
|
}
|
|
|
|
/**
|
|
* smack_flags_to_may - convert S_ to MAY_ values
|
|
* @flags: the S_ value
|
|
*
|
|
* Returns the equivalent MAY_ value
|
|
*/
|
|
static int smack_flags_to_may(int flags)
|
|
{
|
|
int may = 0;
|
|
|
|
if (flags & S_IRUGO)
|
|
may |= MAY_READ;
|
|
if (flags & S_IWUGO)
|
|
may |= MAY_WRITE;
|
|
if (flags & S_IXUGO)
|
|
may |= MAY_EXEC;
|
|
|
|
return may;
|
|
}
|
|
|
|
/**
|
|
* smack_msg_msg_alloc_security - Set the security blob for msg_msg
|
|
* @msg: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_msg_msg_alloc_security(struct msg_msg *msg)
|
|
{
|
|
msg->security = current_security();
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_msg_msg_free_security - Clear the security blob for msg_msg
|
|
* @msg: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_msg_msg_free_security(struct msg_msg *msg)
|
|
{
|
|
msg->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_of_shm - the smack pointer for the shm
|
|
* @shp: the object
|
|
*
|
|
* Returns a pointer to the smack value
|
|
*/
|
|
static char *smack_of_shm(struct shmid_kernel *shp)
|
|
{
|
|
return (char *)shp->shm_perm.security;
|
|
}
|
|
|
|
/**
|
|
* smack_shm_alloc_security - Set the security blob for shm
|
|
* @shp: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_shm_alloc_security(struct shmid_kernel *shp)
|
|
{
|
|
struct kern_ipc_perm *isp = &shp->shm_perm;
|
|
|
|
isp->security = current_security();
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_shm_free_security - Clear the security blob for shm
|
|
* @shp: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_shm_free_security(struct shmid_kernel *shp)
|
|
{
|
|
struct kern_ipc_perm *isp = &shp->shm_perm;
|
|
|
|
isp->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_shm_associate - Smack access check for shm
|
|
* @shp: the object
|
|
* @shmflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_shm_associate(struct shmid_kernel *shp, int shmflg)
|
|
{
|
|
char *ssp = smack_of_shm(shp);
|
|
int may;
|
|
|
|
may = smack_flags_to_may(shmflg);
|
|
return smk_curacc(ssp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_shm_shmctl - Smack access check for shm
|
|
* @shp: the object
|
|
* @cmd: what it wants to do
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_shm_shmctl(struct shmid_kernel *shp, int cmd)
|
|
{
|
|
char *ssp;
|
|
int may;
|
|
|
|
switch (cmd) {
|
|
case IPC_STAT:
|
|
case SHM_STAT:
|
|
may = MAY_READ;
|
|
break;
|
|
case IPC_SET:
|
|
case SHM_LOCK:
|
|
case SHM_UNLOCK:
|
|
case IPC_RMID:
|
|
may = MAY_READWRITE;
|
|
break;
|
|
case IPC_INFO:
|
|
case SHM_INFO:
|
|
/*
|
|
* System level information.
|
|
*/
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
ssp = smack_of_shm(shp);
|
|
return smk_curacc(ssp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_shm_shmat - Smack access for shmat
|
|
* @shp: the object
|
|
* @shmaddr: unused
|
|
* @shmflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_shm_shmat(struct shmid_kernel *shp, char __user *shmaddr,
|
|
int shmflg)
|
|
{
|
|
char *ssp = smack_of_shm(shp);
|
|
int may;
|
|
|
|
may = smack_flags_to_may(shmflg);
|
|
return smk_curacc(ssp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_of_sem - the smack pointer for the sem
|
|
* @sma: the object
|
|
*
|
|
* Returns a pointer to the smack value
|
|
*/
|
|
static char *smack_of_sem(struct sem_array *sma)
|
|
{
|
|
return (char *)sma->sem_perm.security;
|
|
}
|
|
|
|
/**
|
|
* smack_sem_alloc_security - Set the security blob for sem
|
|
* @sma: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_sem_alloc_security(struct sem_array *sma)
|
|
{
|
|
struct kern_ipc_perm *isp = &sma->sem_perm;
|
|
|
|
isp->security = current_security();
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_sem_free_security - Clear the security blob for sem
|
|
* @sma: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_sem_free_security(struct sem_array *sma)
|
|
{
|
|
struct kern_ipc_perm *isp = &sma->sem_perm;
|
|
|
|
isp->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_sem_associate - Smack access check for sem
|
|
* @sma: the object
|
|
* @semflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_sem_associate(struct sem_array *sma, int semflg)
|
|
{
|
|
char *ssp = smack_of_sem(sma);
|
|
int may;
|
|
|
|
may = smack_flags_to_may(semflg);
|
|
return smk_curacc(ssp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_sem_shmctl - Smack access check for sem
|
|
* @sma: the object
|
|
* @cmd: what it wants to do
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_sem_semctl(struct sem_array *sma, int cmd)
|
|
{
|
|
char *ssp;
|
|
int may;
|
|
|
|
switch (cmd) {
|
|
case GETPID:
|
|
case GETNCNT:
|
|
case GETZCNT:
|
|
case GETVAL:
|
|
case GETALL:
|
|
case IPC_STAT:
|
|
case SEM_STAT:
|
|
may = MAY_READ;
|
|
break;
|
|
case SETVAL:
|
|
case SETALL:
|
|
case IPC_RMID:
|
|
case IPC_SET:
|
|
may = MAY_READWRITE;
|
|
break;
|
|
case IPC_INFO:
|
|
case SEM_INFO:
|
|
/*
|
|
* System level information
|
|
*/
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
ssp = smack_of_sem(sma);
|
|
return smk_curacc(ssp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_sem_semop - Smack checks of semaphore operations
|
|
* @sma: the object
|
|
* @sops: unused
|
|
* @nsops: unused
|
|
* @alter: unused
|
|
*
|
|
* Treated as read and write in all cases.
|
|
*
|
|
* Returns 0 if access is allowed, error code otherwise
|
|
*/
|
|
static int smack_sem_semop(struct sem_array *sma, struct sembuf *sops,
|
|
unsigned nsops, int alter)
|
|
{
|
|
char *ssp = smack_of_sem(sma);
|
|
|
|
return smk_curacc(ssp, MAY_READWRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_alloc_security - Set the security blob for msg
|
|
* @msq: the object
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_msg_queue_alloc_security(struct msg_queue *msq)
|
|
{
|
|
struct kern_ipc_perm *kisp = &msq->q_perm;
|
|
|
|
kisp->security = current_security();
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_msg_free_security - Clear the security blob for msg
|
|
* @msq: the object
|
|
*
|
|
* Clears the blob pointer
|
|
*/
|
|
static void smack_msg_queue_free_security(struct msg_queue *msq)
|
|
{
|
|
struct kern_ipc_perm *kisp = &msq->q_perm;
|
|
|
|
kisp->security = NULL;
|
|
}
|
|
|
|
/**
|
|
* smack_of_msq - the smack pointer for the msq
|
|
* @msq: the object
|
|
*
|
|
* Returns a pointer to the smack value
|
|
*/
|
|
static char *smack_of_msq(struct msg_queue *msq)
|
|
{
|
|
return (char *)msq->q_perm.security;
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_associate - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @msqflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_associate(struct msg_queue *msq, int msqflg)
|
|
{
|
|
char *msp = smack_of_msq(msq);
|
|
int may;
|
|
|
|
may = smack_flags_to_may(msqflg);
|
|
return smk_curacc(msp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_msgctl - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @cmd: what it wants to do
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_msgctl(struct msg_queue *msq, int cmd)
|
|
{
|
|
char *msp;
|
|
int may;
|
|
|
|
switch (cmd) {
|
|
case IPC_STAT:
|
|
case MSG_STAT:
|
|
may = MAY_READ;
|
|
break;
|
|
case IPC_SET:
|
|
case IPC_RMID:
|
|
may = MAY_READWRITE;
|
|
break;
|
|
case IPC_INFO:
|
|
case MSG_INFO:
|
|
/*
|
|
* System level information
|
|
*/
|
|
return 0;
|
|
default:
|
|
return -EINVAL;
|
|
}
|
|
|
|
msp = smack_of_msq(msq);
|
|
return smk_curacc(msp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_msgsnd - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @msg: unused
|
|
* @msqflg: access requested
|
|
*
|
|
* Returns 0 if current has the requested access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg,
|
|
int msqflg)
|
|
{
|
|
char *msp = smack_of_msq(msq);
|
|
int rc;
|
|
|
|
rc = smack_flags_to_may(msqflg);
|
|
return smk_curacc(msp, rc);
|
|
}
|
|
|
|
/**
|
|
* smack_msg_queue_msgsnd - Smack access check for msg_queue
|
|
* @msq: the object
|
|
* @msg: unused
|
|
* @target: unused
|
|
* @type: unused
|
|
* @mode: unused
|
|
*
|
|
* Returns 0 if current has read and write access, error code otherwise
|
|
*/
|
|
static int smack_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
|
|
struct task_struct *target, long type, int mode)
|
|
{
|
|
char *msp = smack_of_msq(msq);
|
|
|
|
return smk_curacc(msp, MAY_READWRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_ipc_permission - Smack access for ipc_permission()
|
|
* @ipp: the object permissions
|
|
* @flag: access requested
|
|
*
|
|
* Returns 0 if current has read and write access, error code otherwise
|
|
*/
|
|
static int smack_ipc_permission(struct kern_ipc_perm *ipp, short flag)
|
|
{
|
|
char *isp = ipp->security;
|
|
int may;
|
|
|
|
may = smack_flags_to_may(flag);
|
|
return smk_curacc(isp, may);
|
|
}
|
|
|
|
/**
|
|
* smack_ipc_getsecid - Extract smack security id
|
|
* @ipcp: the object permissions
|
|
* @secid: where result will be saved
|
|
*/
|
|
static void smack_ipc_getsecid(struct kern_ipc_perm *ipp, u32 *secid)
|
|
{
|
|
char *smack = ipp->security;
|
|
|
|
*secid = smack_to_secid(smack);
|
|
}
|
|
|
|
/**
|
|
* smack_d_instantiate - Make sure the blob is correct on an inode
|
|
* @opt_dentry: unused
|
|
* @inode: the object
|
|
*
|
|
* Set the inode's security blob if it hasn't been done already.
|
|
*/
|
|
static void smack_d_instantiate(struct dentry *opt_dentry, struct inode *inode)
|
|
{
|
|
struct super_block *sbp;
|
|
struct superblock_smack *sbsp;
|
|
struct inode_smack *isp;
|
|
char *csp = current_security();
|
|
char *fetched;
|
|
char *final;
|
|
struct dentry *dp;
|
|
|
|
if (inode == NULL)
|
|
return;
|
|
|
|
isp = inode->i_security;
|
|
|
|
mutex_lock(&isp->smk_lock);
|
|
/*
|
|
* If the inode is already instantiated
|
|
* take the quick way out
|
|
*/
|
|
if (isp->smk_flags & SMK_INODE_INSTANT)
|
|
goto unlockandout;
|
|
|
|
sbp = inode->i_sb;
|
|
sbsp = sbp->s_security;
|
|
/*
|
|
* We're going to use the superblock default label
|
|
* if there's no label on the file.
|
|
*/
|
|
final = sbsp->smk_default;
|
|
|
|
/*
|
|
* If this is the root inode the superblock
|
|
* may be in the process of initialization.
|
|
* If that is the case use the root value out
|
|
* of the superblock.
|
|
*/
|
|
if (opt_dentry->d_parent == opt_dentry) {
|
|
isp->smk_inode = sbsp->smk_root;
|
|
isp->smk_flags |= SMK_INODE_INSTANT;
|
|
goto unlockandout;
|
|
}
|
|
|
|
/*
|
|
* This is pretty hackish.
|
|
* Casey says that we shouldn't have to do
|
|
* file system specific code, but it does help
|
|
* with keeping it simple.
|
|
*/
|
|
switch (sbp->s_magic) {
|
|
case SMACK_MAGIC:
|
|
/*
|
|
* Casey says that it's a little embarassing
|
|
* that the smack file system doesn't do
|
|
* extended attributes.
|
|
*/
|
|
final = smack_known_star.smk_known;
|
|
break;
|
|
case PIPEFS_MAGIC:
|
|
/*
|
|
* Casey says pipes are easy (?)
|
|
*/
|
|
final = smack_known_star.smk_known;
|
|
break;
|
|
case DEVPTS_SUPER_MAGIC:
|
|
/*
|
|
* devpts seems content with the label of the task.
|
|
* Programs that change smack have to treat the
|
|
* pty with respect.
|
|
*/
|
|
final = csp;
|
|
break;
|
|
case SOCKFS_MAGIC:
|
|
/*
|
|
* Casey says sockets get the smack of the task.
|
|
*/
|
|
final = csp;
|
|
break;
|
|
case PROC_SUPER_MAGIC:
|
|
/*
|
|
* Casey says procfs appears not to care.
|
|
* The superblock default suffices.
|
|
*/
|
|
break;
|
|
case TMPFS_MAGIC:
|
|
/*
|
|
* Device labels should come from the filesystem,
|
|
* but watch out, because they're volitile,
|
|
* getting recreated on every reboot.
|
|
*/
|
|
final = smack_known_star.smk_known;
|
|
/*
|
|
* No break.
|
|
*
|
|
* If a smack value has been set we want to use it,
|
|
* but since tmpfs isn't giving us the opportunity
|
|
* to set mount options simulate setting the
|
|
* superblock default.
|
|
*/
|
|
default:
|
|
/*
|
|
* This isn't an understood special case.
|
|
* Get the value from the xattr.
|
|
*
|
|
* No xattr support means, alas, no SMACK label.
|
|
* Use the aforeapplied default.
|
|
* It would be curious if the label of the task
|
|
* does not match that assigned.
|
|
*/
|
|
if (inode->i_op->getxattr == NULL)
|
|
break;
|
|
/*
|
|
* Get the dentry for xattr.
|
|
*/
|
|
if (opt_dentry == NULL) {
|
|
dp = d_find_alias(inode);
|
|
if (dp == NULL)
|
|
break;
|
|
} else {
|
|
dp = dget(opt_dentry);
|
|
if (dp == NULL)
|
|
break;
|
|
}
|
|
|
|
fetched = smk_fetch(inode, dp);
|
|
if (fetched != NULL)
|
|
final = fetched;
|
|
|
|
dput(dp);
|
|
break;
|
|
}
|
|
|
|
if (final == NULL)
|
|
isp->smk_inode = csp;
|
|
else
|
|
isp->smk_inode = final;
|
|
|
|
isp->smk_flags |= SMK_INODE_INSTANT;
|
|
|
|
unlockandout:
|
|
mutex_unlock(&isp->smk_lock);
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* smack_getprocattr - Smack process attribute access
|
|
* @p: the object task
|
|
* @name: the name of the attribute in /proc/.../attr
|
|
* @value: where to put the result
|
|
*
|
|
* Places a copy of the task Smack into value
|
|
*
|
|
* Returns the length of the smack label or an error code
|
|
*/
|
|
static int smack_getprocattr(struct task_struct *p, char *name, char **value)
|
|
{
|
|
char *cp;
|
|
int slen;
|
|
|
|
if (strcmp(name, "current") != 0)
|
|
return -EINVAL;
|
|
|
|
cp = kstrdup(task_security(p), GFP_KERNEL);
|
|
if (cp == NULL)
|
|
return -ENOMEM;
|
|
|
|
slen = strlen(cp);
|
|
*value = cp;
|
|
return slen;
|
|
}
|
|
|
|
/**
|
|
* smack_setprocattr - Smack process attribute setting
|
|
* @p: the object task
|
|
* @name: the name of the attribute in /proc/.../attr
|
|
* @value: the value to set
|
|
* @size: the size of the value
|
|
*
|
|
* Sets the Smack value of the task. Only setting self
|
|
* is permitted and only with privilege
|
|
*
|
|
* Returns the length of the smack label or an error code
|
|
*/
|
|
static int smack_setprocattr(struct task_struct *p, char *name,
|
|
void *value, size_t size)
|
|
{
|
|
struct cred *new;
|
|
char *newsmack;
|
|
|
|
/*
|
|
* Changing another process' Smack value is too dangerous
|
|
* and supports no sane use case.
|
|
*/
|
|
if (p != current)
|
|
return -EPERM;
|
|
|
|
if (!capable(CAP_MAC_ADMIN))
|
|
return -EPERM;
|
|
|
|
if (value == NULL || size == 0 || size >= SMK_LABELLEN)
|
|
return -EINVAL;
|
|
|
|
if (strcmp(name, "current") != 0)
|
|
return -EINVAL;
|
|
|
|
newsmack = smk_import(value, size);
|
|
if (newsmack == NULL)
|
|
return -EINVAL;
|
|
|
|
new = prepare_creds();
|
|
if (!new)
|
|
return -ENOMEM;
|
|
new->security = newsmack;
|
|
commit_creds(new);
|
|
return size;
|
|
}
|
|
|
|
/**
|
|
* smack_unix_stream_connect - Smack access on UDS
|
|
* @sock: one socket
|
|
* @other: the other socket
|
|
* @newsk: unused
|
|
*
|
|
* Return 0 if a subject with the smack of sock could access
|
|
* an object with the smack of other, otherwise an error code
|
|
*/
|
|
static int smack_unix_stream_connect(struct socket *sock,
|
|
struct socket *other, struct sock *newsk)
|
|
{
|
|
struct inode *sp = SOCK_INODE(sock);
|
|
struct inode *op = SOCK_INODE(other);
|
|
|
|
return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_READWRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_unix_may_send - Smack access on UDS
|
|
* @sock: one socket
|
|
* @other: the other socket
|
|
*
|
|
* Return 0 if a subject with the smack of sock could access
|
|
* an object with the smack of other, otherwise an error code
|
|
*/
|
|
static int smack_unix_may_send(struct socket *sock, struct socket *other)
|
|
{
|
|
struct inode *sp = SOCK_INODE(sock);
|
|
struct inode *op = SOCK_INODE(other);
|
|
|
|
return smk_access(smk_of_inode(sp), smk_of_inode(op), MAY_WRITE);
|
|
}
|
|
|
|
/**
|
|
* smack_from_secattr - Convert a netlabel attr.mls.lvl/attr.mls.cat
|
|
* pair to smack
|
|
* @sap: netlabel secattr
|
|
* @sip: where to put the result
|
|
*
|
|
* Copies a smack label into sip
|
|
*/
|
|
static void smack_from_secattr(struct netlbl_lsm_secattr *sap, char *sip)
|
|
{
|
|
char smack[SMK_LABELLEN];
|
|
int pcat;
|
|
|
|
if ((sap->flags & NETLBL_SECATTR_MLS_LVL) == 0) {
|
|
/*
|
|
* If there are flags but no level netlabel isn't
|
|
* behaving the way we expect it to.
|
|
*
|
|
* Without guidance regarding the smack value
|
|
* for the packet fall back on the network
|
|
* ambient value.
|
|
*/
|
|
strncpy(sip, smack_net_ambient, SMK_MAXLEN);
|
|
return;
|
|
}
|
|
/*
|
|
* Get the categories, if any
|
|
*/
|
|
memset(smack, '\0', SMK_LABELLEN);
|
|
if ((sap->flags & NETLBL_SECATTR_MLS_CAT) != 0)
|
|
for (pcat = -1;;) {
|
|
pcat = netlbl_secattr_catmap_walk(sap->attr.mls.cat,
|
|
pcat + 1);
|
|
if (pcat < 0)
|
|
break;
|
|
smack_catset_bit(pcat, smack);
|
|
}
|
|
/*
|
|
* If it is CIPSO using smack direct mapping
|
|
* we are already done. WeeHee.
|
|
*/
|
|
if (sap->attr.mls.lvl == smack_cipso_direct) {
|
|
memcpy(sip, smack, SMK_MAXLEN);
|
|
return;
|
|
}
|
|
/*
|
|
* Look it up in the supplied table if it is not a direct mapping.
|
|
*/
|
|
smack_from_cipso(sap->attr.mls.lvl, smack, sip);
|
|
return;
|
|
}
|
|
|
|
/**
|
|
* smack_socket_sock_rcv_skb - Smack packet delivery access check
|
|
* @sk: socket
|
|
* @skb: packet
|
|
*
|
|
* Returns 0 if the packet should be delivered, an error code otherwise
|
|
*/
|
|
static int smack_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
|
|
{
|
|
struct netlbl_lsm_secattr secattr;
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
char smack[SMK_LABELLEN];
|
|
int rc;
|
|
|
|
if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
|
|
return 0;
|
|
|
|
/*
|
|
* Translate what netlabel gave us.
|
|
*/
|
|
memset(smack, '\0', SMK_LABELLEN);
|
|
netlbl_secattr_init(&secattr);
|
|
rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
|
|
if (rc == 0)
|
|
smack_from_secattr(&secattr, smack);
|
|
else
|
|
strncpy(smack, smack_net_ambient, SMK_MAXLEN);
|
|
netlbl_secattr_destroy(&secattr);
|
|
/*
|
|
* Receiving a packet requires that the other end
|
|
* be able to write here. Read access is not required.
|
|
* This is the simplist possible security model
|
|
* for networking.
|
|
*/
|
|
rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
|
|
if (rc != 0)
|
|
netlbl_skbuff_err(skb, rc, 0);
|
|
return rc;
|
|
}
|
|
|
|
/**
|
|
* smack_socket_getpeersec_stream - pull in packet label
|
|
* @sock: the socket
|
|
* @optval: user's destination
|
|
* @optlen: size thereof
|
|
* @len: max thereoe
|
|
*
|
|
* returns zero on success, an error code otherwise
|
|
*/
|
|
static int smack_socket_getpeersec_stream(struct socket *sock,
|
|
char __user *optval,
|
|
int __user *optlen, unsigned len)
|
|
{
|
|
struct socket_smack *ssp;
|
|
int slen;
|
|
int rc = 0;
|
|
|
|
ssp = sock->sk->sk_security;
|
|
slen = strlen(ssp->smk_packet) + 1;
|
|
|
|
if (slen > len)
|
|
rc = -ERANGE;
|
|
else if (copy_to_user(optval, ssp->smk_packet, slen) != 0)
|
|
rc = -EFAULT;
|
|
|
|
if (put_user(slen, optlen) != 0)
|
|
rc = -EFAULT;
|
|
|
|
return rc;
|
|
}
|
|
|
|
|
|
/**
|
|
* smack_socket_getpeersec_dgram - pull in packet label
|
|
* @sock: the socket
|
|
* @skb: packet data
|
|
* @secid: pointer to where to put the secid of the packet
|
|
*
|
|
* Sets the netlabel socket state on sk from parent
|
|
*/
|
|
static int smack_socket_getpeersec_dgram(struct socket *sock,
|
|
struct sk_buff *skb, u32 *secid)
|
|
|
|
{
|
|
struct netlbl_lsm_secattr secattr;
|
|
struct sock *sk;
|
|
char smack[SMK_LABELLEN];
|
|
int family = PF_INET;
|
|
u32 s;
|
|
int rc;
|
|
|
|
/*
|
|
* Only works for families with packets.
|
|
*/
|
|
if (sock != NULL) {
|
|
sk = sock->sk;
|
|
if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
|
|
return 0;
|
|
family = sk->sk_family;
|
|
}
|
|
/*
|
|
* Translate what netlabel gave us.
|
|
*/
|
|
memset(smack, '\0', SMK_LABELLEN);
|
|
netlbl_secattr_init(&secattr);
|
|
rc = netlbl_skbuff_getattr(skb, family, &secattr);
|
|
if (rc == 0)
|
|
smack_from_secattr(&secattr, smack);
|
|
netlbl_secattr_destroy(&secattr);
|
|
|
|
/*
|
|
* Give up if we couldn't get anything
|
|
*/
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
s = smack_to_secid(smack);
|
|
if (s == 0)
|
|
return -EINVAL;
|
|
|
|
*secid = s;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_sock_graft - graft access state between two sockets
|
|
* @sk: fresh sock
|
|
* @parent: donor socket
|
|
*
|
|
* Sets the netlabel socket state on sk from parent
|
|
*/
|
|
static void smack_sock_graft(struct sock *sk, struct socket *parent)
|
|
{
|
|
struct socket_smack *ssp;
|
|
int rc;
|
|
|
|
if (sk == NULL)
|
|
return;
|
|
|
|
if (sk->sk_family != PF_INET && sk->sk_family != PF_INET6)
|
|
return;
|
|
|
|
ssp = sk->sk_security;
|
|
ssp->smk_in = ssp->smk_out = current_security();
|
|
ssp->smk_packet[0] = '\0';
|
|
|
|
rc = smack_netlabel(sk);
|
|
if (rc != 0)
|
|
printk(KERN_WARNING "Smack: \"%s\" netlbl error %d.\n",
|
|
__func__, -rc);
|
|
}
|
|
|
|
/**
|
|
* smack_inet_conn_request - Smack access check on connect
|
|
* @sk: socket involved
|
|
* @skb: packet
|
|
* @req: unused
|
|
*
|
|
* Returns 0 if a task with the packet label could write to
|
|
* the socket, otherwise an error code
|
|
*/
|
|
static int smack_inet_conn_request(struct sock *sk, struct sk_buff *skb,
|
|
struct request_sock *req)
|
|
{
|
|
struct netlbl_lsm_secattr skb_secattr;
|
|
struct socket_smack *ssp = sk->sk_security;
|
|
char smack[SMK_LABELLEN];
|
|
int rc;
|
|
|
|
if (skb == NULL)
|
|
return -EACCES;
|
|
|
|
memset(smack, '\0', SMK_LABELLEN);
|
|
netlbl_secattr_init(&skb_secattr);
|
|
rc = netlbl_skbuff_getattr(skb, sk->sk_family, &skb_secattr);
|
|
if (rc == 0)
|
|
smack_from_secattr(&skb_secattr, smack);
|
|
else
|
|
strncpy(smack, smack_known_huh.smk_known, SMK_MAXLEN);
|
|
netlbl_secattr_destroy(&skb_secattr);
|
|
/*
|
|
* Receiving a packet requires that the other end
|
|
* be able to write here. Read access is not required.
|
|
*
|
|
* If the request is successful save the peer's label
|
|
* so that SO_PEERCRED can report it.
|
|
*/
|
|
rc = smk_access(smack, ssp->smk_in, MAY_WRITE);
|
|
if (rc == 0)
|
|
strncpy(ssp->smk_packet, smack, SMK_MAXLEN);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
* Key management security hooks
|
|
*
|
|
* Casey has not tested key support very heavily.
|
|
* The permission check is most likely too restrictive.
|
|
* If you care about keys please have a look.
|
|
*/
|
|
#ifdef CONFIG_KEYS
|
|
|
|
/**
|
|
* smack_key_alloc - Set the key security blob
|
|
* @key: object
|
|
* @cred: the credentials to use
|
|
* @flags: unused
|
|
*
|
|
* No allocation required
|
|
*
|
|
* Returns 0
|
|
*/
|
|
static int smack_key_alloc(struct key *key, const struct cred *cred,
|
|
unsigned long flags)
|
|
{
|
|
key->security = cred->security;
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_key_free - Clear the key security blob
|
|
* @key: the object
|
|
*
|
|
* Clear the blob pointer
|
|
*/
|
|
static void smack_key_free(struct key *key)
|
|
{
|
|
key->security = NULL;
|
|
}
|
|
|
|
/*
|
|
* smack_key_permission - Smack access on a key
|
|
* @key_ref: gets to the object
|
|
* @cred: the credentials to use
|
|
* @perm: unused
|
|
*
|
|
* Return 0 if the task has read and write to the object,
|
|
* an error code otherwise
|
|
*/
|
|
static int smack_key_permission(key_ref_t key_ref,
|
|
const struct cred *cred, key_perm_t perm)
|
|
{
|
|
struct key *keyp;
|
|
|
|
keyp = key_ref_to_ptr(key_ref);
|
|
if (keyp == NULL)
|
|
return -EINVAL;
|
|
/*
|
|
* If the key hasn't been initialized give it access so that
|
|
* it may do so.
|
|
*/
|
|
if (keyp->security == NULL)
|
|
return 0;
|
|
/*
|
|
* This should not occur
|
|
*/
|
|
if (cred->security == NULL)
|
|
return -EACCES;
|
|
|
|
return smk_access(cred->security, keyp->security, MAY_READWRITE);
|
|
}
|
|
#endif /* CONFIG_KEYS */
|
|
|
|
/*
|
|
* Smack Audit hooks
|
|
*
|
|
* Audit requires a unique representation of each Smack specific
|
|
* rule. This unique representation is used to distinguish the
|
|
* object to be audited from remaining kernel objects and also
|
|
* works as a glue between the audit hooks.
|
|
*
|
|
* Since repository entries are added but never deleted, we'll use
|
|
* the smack_known label address related to the given audit rule as
|
|
* the needed unique representation. This also better fits the smack
|
|
* model where nearly everything is a label.
|
|
*/
|
|
#ifdef CONFIG_AUDIT
|
|
|
|
/**
|
|
* smack_audit_rule_init - Initialize a smack audit rule
|
|
* @field: audit rule fields given from user-space (audit.h)
|
|
* @op: required testing operator (=, !=, >, <, ...)
|
|
* @rulestr: smack label to be audited
|
|
* @vrule: pointer to save our own audit rule representation
|
|
*
|
|
* Prepare to audit cases where (@field @op @rulestr) is true.
|
|
* The label to be audited is created if necessay.
|
|
*/
|
|
static int smack_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
|
|
{
|
|
char **rule = (char **)vrule;
|
|
*rule = NULL;
|
|
|
|
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
|
|
return -EINVAL;
|
|
|
|
if (op != AUDIT_EQUAL && op != AUDIT_NOT_EQUAL)
|
|
return -EINVAL;
|
|
|
|
*rule = smk_import(rulestr, 0);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_audit_rule_known - Distinguish Smack audit rules
|
|
* @krule: rule of interest, in Audit kernel representation format
|
|
*
|
|
* This is used to filter Smack rules from remaining Audit ones.
|
|
* If it's proved that this rule belongs to us, the
|
|
* audit_rule_match hook will be called to do the final judgement.
|
|
*/
|
|
static int smack_audit_rule_known(struct audit_krule *krule)
|
|
{
|
|
struct audit_field *f;
|
|
int i;
|
|
|
|
for (i = 0; i < krule->field_count; i++) {
|
|
f = &krule->fields[i];
|
|
|
|
if (f->type == AUDIT_SUBJ_USER || f->type == AUDIT_OBJ_USER)
|
|
return 1;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_audit_rule_match - Audit given object ?
|
|
* @secid: security id for identifying the object to test
|
|
* @field: audit rule flags given from user-space
|
|
* @op: required testing operator
|
|
* @vrule: smack internal rule presentation
|
|
* @actx: audit context associated with the check
|
|
*
|
|
* The core Audit hook. It's used to take the decision of
|
|
* whether to audit or not to audit a given object.
|
|
*/
|
|
static int smack_audit_rule_match(u32 secid, u32 field, u32 op, void *vrule,
|
|
struct audit_context *actx)
|
|
{
|
|
char *smack;
|
|
char *rule = vrule;
|
|
|
|
if (!rule) {
|
|
audit_log(actx, GFP_KERNEL, AUDIT_SELINUX_ERR,
|
|
"Smack: missing rule\n");
|
|
return -ENOENT;
|
|
}
|
|
|
|
if (field != AUDIT_SUBJ_USER && field != AUDIT_OBJ_USER)
|
|
return 0;
|
|
|
|
smack = smack_from_secid(secid);
|
|
|
|
/*
|
|
* No need to do string comparisons. If a match occurs,
|
|
* both pointers will point to the same smack_known
|
|
* label.
|
|
*/
|
|
if (op == AUDIT_EQUAL)
|
|
return (rule == smack);
|
|
if (op == AUDIT_NOT_EQUAL)
|
|
return (rule != smack);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* smack_audit_rule_free - free smack rule representation
|
|
* @vrule: rule to be freed.
|
|
*
|
|
* No memory was allocated.
|
|
*/
|
|
static void smack_audit_rule_free(void *vrule)
|
|
{
|
|
/* No-op */
|
|
}
|
|
|
|
#endif /* CONFIG_AUDIT */
|
|
|
|
/*
|
|
* smack_secid_to_secctx - return the smack label for a secid
|
|
* @secid: incoming integer
|
|
* @secdata: destination
|
|
* @seclen: how long it is
|
|
*
|
|
* Exists for networking code.
|
|
*/
|
|
static int smack_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
|
|
{
|
|
char *sp = smack_from_secid(secid);
|
|
|
|
*secdata = sp;
|
|
*seclen = strlen(sp);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* smack_secctx_to_secid - return the secid for a smack label
|
|
* @secdata: smack label
|
|
* @seclen: how long result is
|
|
* @secid: outgoing integer
|
|
*
|
|
* Exists for audit and networking code.
|
|
*/
|
|
static int smack_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
|
|
{
|
|
*secid = smack_to_secid(secdata);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* smack_release_secctx - don't do anything.
|
|
* @key_ref: unused
|
|
* @context: unused
|
|
* @perm: unused
|
|
*
|
|
* Exists to make sure nothing gets done, and properly
|
|
*/
|
|
static void smack_release_secctx(char *secdata, u32 seclen)
|
|
{
|
|
}
|
|
|
|
struct security_operations smack_ops = {
|
|
.name = "smack",
|
|
|
|
.ptrace_may_access = smack_ptrace_may_access,
|
|
.ptrace_traceme = smack_ptrace_traceme,
|
|
.capget = cap_capget,
|
|
.capset = cap_capset,
|
|
.capable = cap_capable,
|
|
.syslog = smack_syslog,
|
|
.settime = cap_settime,
|
|
.vm_enough_memory = cap_vm_enough_memory,
|
|
|
|
.bprm_set_creds = cap_bprm_set_creds,
|
|
.bprm_secureexec = cap_bprm_secureexec,
|
|
|
|
.sb_alloc_security = smack_sb_alloc_security,
|
|
.sb_free_security = smack_sb_free_security,
|
|
.sb_copy_data = smack_sb_copy_data,
|
|
.sb_kern_mount = smack_sb_kern_mount,
|
|
.sb_statfs = smack_sb_statfs,
|
|
.sb_mount = smack_sb_mount,
|
|
.sb_umount = smack_sb_umount,
|
|
|
|
.inode_alloc_security = smack_inode_alloc_security,
|
|
.inode_free_security = smack_inode_free_security,
|
|
.inode_init_security = smack_inode_init_security,
|
|
.inode_link = smack_inode_link,
|
|
.inode_unlink = smack_inode_unlink,
|
|
.inode_rmdir = smack_inode_rmdir,
|
|
.inode_rename = smack_inode_rename,
|
|
.inode_permission = smack_inode_permission,
|
|
.inode_setattr = smack_inode_setattr,
|
|
.inode_getattr = smack_inode_getattr,
|
|
.inode_setxattr = smack_inode_setxattr,
|
|
.inode_post_setxattr = smack_inode_post_setxattr,
|
|
.inode_getxattr = smack_inode_getxattr,
|
|
.inode_removexattr = smack_inode_removexattr,
|
|
.inode_need_killpriv = cap_inode_need_killpriv,
|
|
.inode_killpriv = cap_inode_killpriv,
|
|
.inode_getsecurity = smack_inode_getsecurity,
|
|
.inode_setsecurity = smack_inode_setsecurity,
|
|
.inode_listsecurity = smack_inode_listsecurity,
|
|
.inode_getsecid = smack_inode_getsecid,
|
|
|
|
.file_permission = smack_file_permission,
|
|
.file_alloc_security = smack_file_alloc_security,
|
|
.file_free_security = smack_file_free_security,
|
|
.file_ioctl = smack_file_ioctl,
|
|
.file_lock = smack_file_lock,
|
|
.file_fcntl = smack_file_fcntl,
|
|
.file_set_fowner = smack_file_set_fowner,
|
|
.file_send_sigiotask = smack_file_send_sigiotask,
|
|
.file_receive = smack_file_receive,
|
|
|
|
.cred_free = smack_cred_free,
|
|
.cred_prepare = smack_cred_prepare,
|
|
.cred_commit = smack_cred_commit,
|
|
.kernel_act_as = smack_kernel_act_as,
|
|
.kernel_create_files_as = smack_kernel_create_files_as,
|
|
.task_fix_setuid = cap_task_fix_setuid,
|
|
.task_setpgid = smack_task_setpgid,
|
|
.task_getpgid = smack_task_getpgid,
|
|
.task_getsid = smack_task_getsid,
|
|
.task_getsecid = smack_task_getsecid,
|
|
.task_setnice = smack_task_setnice,
|
|
.task_setioprio = smack_task_setioprio,
|
|
.task_getioprio = smack_task_getioprio,
|
|
.task_setscheduler = smack_task_setscheduler,
|
|
.task_getscheduler = smack_task_getscheduler,
|
|
.task_movememory = smack_task_movememory,
|
|
.task_kill = smack_task_kill,
|
|
.task_wait = smack_task_wait,
|
|
.task_to_inode = smack_task_to_inode,
|
|
.task_prctl = cap_task_prctl,
|
|
|
|
.ipc_permission = smack_ipc_permission,
|
|
.ipc_getsecid = smack_ipc_getsecid,
|
|
|
|
.msg_msg_alloc_security = smack_msg_msg_alloc_security,
|
|
.msg_msg_free_security = smack_msg_msg_free_security,
|
|
|
|
.msg_queue_alloc_security = smack_msg_queue_alloc_security,
|
|
.msg_queue_free_security = smack_msg_queue_free_security,
|
|
.msg_queue_associate = smack_msg_queue_associate,
|
|
.msg_queue_msgctl = smack_msg_queue_msgctl,
|
|
.msg_queue_msgsnd = smack_msg_queue_msgsnd,
|
|
.msg_queue_msgrcv = smack_msg_queue_msgrcv,
|
|
|
|
.shm_alloc_security = smack_shm_alloc_security,
|
|
.shm_free_security = smack_shm_free_security,
|
|
.shm_associate = smack_shm_associate,
|
|
.shm_shmctl = smack_shm_shmctl,
|
|
.shm_shmat = smack_shm_shmat,
|
|
|
|
.sem_alloc_security = smack_sem_alloc_security,
|
|
.sem_free_security = smack_sem_free_security,
|
|
.sem_associate = smack_sem_associate,
|
|
.sem_semctl = smack_sem_semctl,
|
|
.sem_semop = smack_sem_semop,
|
|
|
|
.netlink_send = cap_netlink_send,
|
|
.netlink_recv = cap_netlink_recv,
|
|
|
|
.d_instantiate = smack_d_instantiate,
|
|
|
|
.getprocattr = smack_getprocattr,
|
|
.setprocattr = smack_setprocattr,
|
|
|
|
.unix_stream_connect = smack_unix_stream_connect,
|
|
.unix_may_send = smack_unix_may_send,
|
|
|
|
.socket_post_create = smack_socket_post_create,
|
|
.socket_sock_rcv_skb = smack_socket_sock_rcv_skb,
|
|
.socket_getpeersec_stream = smack_socket_getpeersec_stream,
|
|
.socket_getpeersec_dgram = smack_socket_getpeersec_dgram,
|
|
.sk_alloc_security = smack_sk_alloc_security,
|
|
.sk_free_security = smack_sk_free_security,
|
|
.sock_graft = smack_sock_graft,
|
|
.inet_conn_request = smack_inet_conn_request,
|
|
|
|
/* key management security hooks */
|
|
#ifdef CONFIG_KEYS
|
|
.key_alloc = smack_key_alloc,
|
|
.key_free = smack_key_free,
|
|
.key_permission = smack_key_permission,
|
|
#endif /* CONFIG_KEYS */
|
|
|
|
/* Audit hooks */
|
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#ifdef CONFIG_AUDIT
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.audit_rule_init = smack_audit_rule_init,
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.audit_rule_known = smack_audit_rule_known,
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.audit_rule_match = smack_audit_rule_match,
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.audit_rule_free = smack_audit_rule_free,
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#endif /* CONFIG_AUDIT */
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.secid_to_secctx = smack_secid_to_secctx,
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.secctx_to_secid = smack_secctx_to_secid,
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.release_secctx = smack_release_secctx,
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};
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/**
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* smack_init - initialize the smack system
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*
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* Returns 0
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*/
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static __init int smack_init(void)
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{
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struct cred *cred;
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if (!security_module_enable(&smack_ops))
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return 0;
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printk(KERN_INFO "Smack: Initializing.\n");
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/*
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* Set the security state for the initial task.
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*/
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cred = (struct cred *) current->cred;
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cred->security = &smack_known_floor.smk_known;
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/*
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* Initialize locks
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*/
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spin_lock_init(&smack_known_unset.smk_cipsolock);
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spin_lock_init(&smack_known_huh.smk_cipsolock);
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spin_lock_init(&smack_known_hat.smk_cipsolock);
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spin_lock_init(&smack_known_star.smk_cipsolock);
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spin_lock_init(&smack_known_floor.smk_cipsolock);
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spin_lock_init(&smack_known_invalid.smk_cipsolock);
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/*
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* Register with LSM
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*/
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if (register_security(&smack_ops))
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panic("smack: Unable to register with kernel.\n");
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return 0;
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}
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/*
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* Smack requires early initialization in order to label
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* all processes and objects when they are created.
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*/
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security_initcall(smack_init);
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