From bfcec7087458812f575d9022b2d151641f34ee84 Mon Sep 17 00:00:00 2001 From: Jeff Layton Date: Wed, 10 Oct 2012 15:25:23 -0400 Subject: [PATCH] audit: set the name_len in audit_inode for parent lookups Currently, this gets set mostly by happenstance when we call into audit_inode_child. While that might be a little more efficient, it seems wrong. If the syscall ends up failing before audit_inode_child ever gets called, then you'll have an audit_names record that shows the full path but has the parent inode info attached. Fix this by passing in a parent flag when we call audit_inode that gets set to the value of LOOKUP_PARENT. We can then fix up the pathname for the audit entry correctly from the get-go. While we're at it, clean up the no-op macro for audit_inode in the !CONFIG_AUDITSYSCALL case. Signed-off-by: Jeff Layton Signed-off-by: Al Viro --- fs/namei.c | 14 +++++++------- fs/open.c | 4 ++-- fs/xattr.c | 8 ++++---- include/linux/audit.h | 15 ++++++++++----- ipc/mqueue.c | 8 ++++---- kernel/audit.h | 1 + kernel/auditfilter.c | 30 ++++++++++++++++++++++++++++++ kernel/auditsc.c | 41 +++++++++++++++++++++++++++++------------ 8 files changed, 87 insertions(+), 34 deletions(-) diff --git a/fs/namei.c b/fs/namei.c index a7ad35c66807..6a92d988573f 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -1973,7 +1973,7 @@ static int do_path_lookup(int dfd, const char *name, retval = path_lookupat(dfd, name, flags | LOOKUP_REVAL, nd); if (likely(!retval)) - audit_inode(name, nd->path.dentry); + audit_inode(name, nd->path.dentry, flags & LOOKUP_PARENT); return retval; } @@ -2648,7 +2648,7 @@ static int do_last(struct nameidata *nd, struct path *path, error = complete_walk(nd); if (error) return error; - audit_inode(pathname, nd->path.dentry); + audit_inode(pathname, nd->path.dentry, 0); if (open_flag & O_CREAT) { error = -EISDIR; goto out; @@ -2658,7 +2658,7 @@ static int do_last(struct nameidata *nd, struct path *path, error = complete_walk(nd); if (error) return error; - audit_inode(pathname, dir); + audit_inode(pathname, dir, 0); goto finish_open; } @@ -2687,7 +2687,7 @@ static int do_last(struct nameidata *nd, struct path *path, if (error) return error; - audit_inode(pathname, dir); + audit_inode(pathname, dir, 0); error = -EISDIR; /* trailing slashes? */ if (nd->last.name[nd->last.len]) @@ -2717,7 +2717,7 @@ static int do_last(struct nameidata *nd, struct path *path, !S_ISREG(file->f_path.dentry->d_inode->i_mode)) will_truncate = false; - audit_inode(pathname, file->f_path.dentry); + audit_inode(pathname, file->f_path.dentry, 0); goto opened; } @@ -2734,7 +2734,7 @@ static int do_last(struct nameidata *nd, struct path *path, * create/update audit record if it already exists. */ if (path->dentry->d_inode) - audit_inode(pathname, path->dentry); + audit_inode(pathname, path->dentry, 0); /* * If atomic_open() acquired write access it is dropped now due to @@ -2799,7 +2799,7 @@ static int do_last(struct nameidata *nd, struct path *path, error = -ENOTDIR; if ((nd->flags & LOOKUP_DIRECTORY) && !nd->inode->i_op->lookup) goto out; - audit_inode(pathname, nd->path.dentry); + audit_inode(pathname, nd->path.dentry, 0); finish_open: if (!S_ISREG(nd->inode->i_mode)) will_truncate = false; diff --git a/fs/open.c b/fs/open.c index 44da0feeca2c..a015437e1535 100644 --- a/fs/open.c +++ b/fs/open.c @@ -478,7 +478,7 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, umode_t, mode) file = fget(fd); if (file) { - audit_inode(NULL, file->f_path.dentry); + audit_inode(NULL, file->f_path.dentry, 0); err = chmod_common(&file->f_path, mode); fput(file); } @@ -588,7 +588,7 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) error = mnt_want_write_file(f.file); if (error) goto out_fput; - audit_inode(NULL, f.file->f_path.dentry); + audit_inode(NULL, f.file->f_path.dentry, 0); error = chown_common(&f.file->f_path, user, group); mnt_drop_write_file(f.file); out_fput: diff --git a/fs/xattr.c b/fs/xattr.c index 1780f062dbaf..e164dddb8e96 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -412,7 +412,7 @@ SYSCALL_DEFINE5(fsetxattr, int, fd, const char __user *, name, if (!f.file) return error; dentry = f.file->f_path.dentry; - audit_inode(NULL, dentry); + audit_inode(NULL, dentry, 0); error = mnt_want_write_file(f.file); if (!error) { error = setxattr(dentry, name, value, size, flags); @@ -507,7 +507,7 @@ SYSCALL_DEFINE4(fgetxattr, int, fd, const char __user *, name, if (!f.file) return error; - audit_inode(NULL, f.file->f_path.dentry); + audit_inode(NULL, f.file->f_path.dentry, 0); error = getxattr(f.file->f_path.dentry, name, value, size); fdput(f); return error; @@ -586,7 +586,7 @@ SYSCALL_DEFINE3(flistxattr, int, fd, char __user *, list, size_t, size) if (!f.file) return error; - audit_inode(NULL, f.file->f_path.dentry); + audit_inode(NULL, f.file->f_path.dentry, 0); error = listxattr(f.file->f_path.dentry, list, size); fdput(f); return error; @@ -655,7 +655,7 @@ SYSCALL_DEFINE2(fremovexattr, int, fd, const char __user *, name) if (!f.file) return error; dentry = f.file->f_path.dentry; - audit_inode(NULL, dentry); + audit_inode(NULL, dentry, 0); error = mnt_want_write_file(f.file); if (!error) { error = removexattr(dentry, name); diff --git a/include/linux/audit.h b/include/linux/audit.h index 26408934ef2d..b11f517dce04 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -456,6 +456,7 @@ extern int audit_classify_arch(int arch); /* audit_names->type values */ #define AUDIT_TYPE_UNKNOWN 0 /* we don't know yet */ #define AUDIT_TYPE_NORMAL 1 /* a "normal" audit record */ +#define AUDIT_TYPE_PARENT 2 /* a parent audit record */ #ifdef CONFIG_AUDITSYSCALL /* These are defined in auditsc.c */ @@ -468,7 +469,8 @@ extern void __audit_syscall_entry(int arch, extern void __audit_syscall_exit(int ret_success, long ret_value); extern void __audit_getname(const char *name); extern void audit_putname(const char *name); -extern void __audit_inode(const char *name, const struct dentry *dentry); +extern void __audit_inode(const char *name, const struct dentry *dentry, + unsigned int parent); extern void __audit_inode_child(const struct inode *parent, const struct dentry *dentry); extern void __audit_seccomp(unsigned long syscall, long signr, int code); @@ -505,9 +507,10 @@ static inline void audit_getname(const char *name) if (unlikely(!audit_dummy_context())) __audit_getname(name); } -static inline void audit_inode(const char *name, const struct dentry *dentry) { +static inline void audit_inode(const char *name, const struct dentry *dentry, + unsigned int parent) { if (unlikely(!audit_dummy_context())) - __audit_inode(name, dentry); + __audit_inode(name, dentry, parent); } static inline void audit_inode_child(const struct inode *parent, const struct dentry *dentry) { @@ -660,12 +663,14 @@ static inline void audit_getname(const char *name) { } static inline void audit_putname(const char *name) { } -static inline void __audit_inode(const char *name, const struct dentry *dentry) +static inline void __audit_inode(const char *name, const struct dentry *dentry, + unsigned int parent) { } static inline void __audit_inode_child(const struct inode *parent, const struct dentry *dentry) { } -static inline void audit_inode(const char *name, const struct dentry *dentry) +static inline void audit_inode(const char *name, const struct dentry *dentry, + unsigned int parent) { } static inline void audit_inode_child(const struct inode *parent, const struct dentry *dentry) diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 6b97e2466fad..9553ed006042 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -804,7 +804,7 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, if (oflag & O_CREAT) { if (path.dentry->d_inode) { /* entry already exists */ - audit_inode(name, path.dentry); + audit_inode(name, path.dentry, 0); if (oflag & O_EXCL) { error = -EEXIST; goto out; @@ -824,7 +824,7 @@ SYSCALL_DEFINE4(mq_open, const char __user *, u_name, int, oflag, umode_t, mode, error = -ENOENT; goto out; } - audit_inode(name, path.dentry); + audit_inode(name, path.dentry, 0); filp = do_open(&path, oflag); } @@ -978,7 +978,7 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr, goto out_fput; } info = MQUEUE_I(inode); - audit_inode(NULL, f.file->f_path.dentry); + audit_inode(NULL, f.file->f_path.dentry, 0); if (unlikely(!(f.file->f_mode & FMODE_WRITE))) { ret = -EBADF; @@ -1094,7 +1094,7 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr, goto out_fput; } info = MQUEUE_I(inode); - audit_inode(NULL, f.file->f_path.dentry); + audit_inode(NULL, f.file->f_path.dentry, 0); if (unlikely(!(f.file->f_mode & FMODE_READ))) { ret = -EBADF; diff --git a/kernel/audit.h b/kernel/audit.h index 9eb3d79482b6..163b9a5d9441 100644 --- a/kernel/audit.h +++ b/kernel/audit.h @@ -78,6 +78,7 @@ extern int audit_match_class(int class, unsigned syscall); extern int audit_comparator(const u32 left, const u32 op, const u32 right); extern int audit_uid_comparator(kuid_t left, u32 op, kuid_t right); extern int audit_gid_comparator(kgid_t left, u32 op, kgid_t right); +extern int parent_len(const char *path); extern int audit_compare_dname_path(const char *dname, const char *path, int *dirlen); extern struct sk_buff * audit_make_reply(int pid, int seq, int type, diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c index c4bcdbaf4d4d..71bb13598df3 100644 --- a/kernel/auditfilter.c +++ b/kernel/auditfilter.c @@ -1298,6 +1298,36 @@ int audit_gid_comparator(kgid_t left, u32 op, kgid_t right) } } +/** + * parent_len - find the length of the parent portion of a pathname + * @path: pathname of which to determine length + */ +int parent_len(const char *path) +{ + int plen; + const char *p; + + plen = strlen(path); + + if (plen == 0) + return plen; + + /* disregard trailing slashes */ + p = path + plen - 1; + while ((*p == '/') && (p > path)) + p--; + + /* walk backward until we find the next slash or hit beginning */ + while ((*p != '/') && (p > path)) + p--; + + /* did we find a slash? Then increment to include it in path */ + if (*p == '/') + p++; + + return p - path; +} + /* Compare given dentry name with last component in given path, * return of 0 indicates a match. */ int audit_compare_dname_path(const char *dname, const char *path, diff --git a/kernel/auditsc.c b/kernel/auditsc.c index 19b232f86d70..b87b28947acc 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -2135,13 +2135,13 @@ static void audit_copy_inode(struct audit_names *name, const struct dentry *dent } /** - * audit_inode - store the inode and device from a lookup + * __audit_inode - store the inode and device from a lookup * @name: name being audited * @dentry: dentry being audited - * - * Called from fs/namei.c:path_lookup(). + * @parent: does this dentry represent the parent? */ -void __audit_inode(const char *name, const struct dentry *dentry) +void __audit_inode(const char *name, const struct dentry *dentry, + unsigned int parent) { struct audit_context *context = current->audit_context; const struct inode *inode = dentry->d_inode; @@ -2154,19 +2154,38 @@ void __audit_inode(const char *name, const struct dentry *dentry) goto out_alloc; list_for_each_entry_reverse(n, &context->names_list, list) { - if (n->name == name) - goto out; + /* does the name pointer match? */ + if (n->name != name) + continue; + + /* match the correct record type */ + if (parent) { + if (n->type == AUDIT_TYPE_PARENT || + n->type == AUDIT_TYPE_UNKNOWN) + goto out; + } else { + if (n->type != AUDIT_TYPE_PARENT) + goto out; + } } out_alloc: - /* unable to find the name from a previous getname() */ + /* unable to find the name from a previous getname(). Allocate a new + * anonymous entry. + */ n = audit_alloc_name(context, AUDIT_TYPE_NORMAL); if (!n) return; out: + if (parent) { + n->name_len = n->name ? parent_len(n->name) : AUDIT_NAME_FULL; + n->type = AUDIT_TYPE_PARENT; + } else { + n->name_len = AUDIT_NAME_FULL; + n->type = AUDIT_TYPE_NORMAL; + } handle_path(dentry); audit_copy_inode(n, dentry, inode); - n->type = AUDIT_TYPE_NORMAL; } /** @@ -2190,7 +2209,6 @@ void __audit_inode_child(const struct inode *parent, const struct inode *inode = dentry->d_inode; const char *dname = dentry->d_name.name; struct audit_names *n; - int dirlen = 0; if (!context->in_syscall) return; @@ -2204,8 +2222,7 @@ void __audit_inode_child(const struct inode *parent, continue; if (n->ino == parent->i_ino && - !audit_compare_dname_path(dname, n->name, &dirlen)) { - n->name_len = dirlen; /* update parent data in place */ + !audit_compare_dname_path(dname, n->name, NULL)) { found_parent = n->name; goto add_names; } @@ -2218,7 +2235,7 @@ void __audit_inode_child(const struct inode *parent, /* strcmp() is the more likely scenario */ if (!strcmp(dname, n->name) || - !audit_compare_dname_path(dname, n->name, &dirlen)) { + !audit_compare_dname_path(dname, n->name, NULL)) { if (inode) audit_copy_inode(n, dentry, inode); else