106 lines
2.5 KiB
C
106 lines
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext4/symlink.c
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*
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* Only fast symlinks left here - the rest is done by generic code. AV, 1999
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/symlink.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* ext4 symlink handling code
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*/
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#include <linux/fs.h>
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#include <linux/namei.h>
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#include "ext4.h"
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#include "xattr.h"
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static const char *ext4_encrypted_get_link(struct dentry *dentry,
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struct inode *inode,
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struct delayed_call *done)
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{
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struct page *cpage = NULL;
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char *caddr, *paddr = NULL;
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struct fscrypt_str cstr, pstr;
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struct fscrypt_symlink_data *sd;
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int res;
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u32 max_size = inode->i_sb->s_blocksize;
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if (!dentry)
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return ERR_PTR(-ECHILD);
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res = fscrypt_get_encryption_info(inode);
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if (res)
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return ERR_PTR(res);
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if (ext4_inode_is_fast_symlink(inode)) {
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caddr = (char *) EXT4_I(inode)->i_data;
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max_size = sizeof(EXT4_I(inode)->i_data);
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} else {
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cpage = read_mapping_page(inode->i_mapping, 0, NULL);
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if (IS_ERR(cpage))
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return ERR_CAST(cpage);
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caddr = page_address(cpage);
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}
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/* Symlink is encrypted */
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sd = (struct fscrypt_symlink_data *)caddr;
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cstr.name = sd->encrypted_path;
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cstr.len = le16_to_cpu(sd->len);
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if ((cstr.len + sizeof(struct fscrypt_symlink_data) - 1) > max_size) {
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/* Symlink data on the disk is corrupted */
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res = -EFSCORRUPTED;
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goto errout;
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}
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res = fscrypt_fname_alloc_buffer(inode, cstr.len, &pstr);
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if (res)
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goto errout;
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paddr = pstr.name;
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res = fscrypt_fname_disk_to_usr(inode, 0, 0, &cstr, &pstr);
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if (res)
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goto errout;
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/* Null-terminate the name */
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paddr[pstr.len] = '\0';
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if (cpage)
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put_page(cpage);
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set_delayed_call(done, kfree_link, paddr);
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return paddr;
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errout:
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if (cpage)
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put_page(cpage);
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kfree(paddr);
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return ERR_PTR(res);
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}
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const struct inode_operations ext4_encrypted_symlink_inode_operations = {
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.get_link = ext4_encrypted_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_getattr,
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.listxattr = ext4_listxattr,
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};
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const struct inode_operations ext4_symlink_inode_operations = {
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.get_link = page_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_getattr,
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.listxattr = ext4_listxattr,
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};
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const struct inode_operations ext4_fast_symlink_inode_operations = {
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.get_link = simple_get_link,
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.setattr = ext4_setattr,
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.getattr = ext4_getattr,
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.listxattr = ext4_listxattr,
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};
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