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audit: set the name_len in audit_inode for parent lookups

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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 <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Jeff Layton 2012-10-10 15:25:23 -04:00 committed by Al Viro
parent 78e2e802a8
commit bfcec70874
8 changed files with 87 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
fs/namei.c
View File

@ -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 @@ retry_lookup:
!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 @@ retry_lookup:
* 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 @@ finish_lookup:
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;

4
fs/open.c
View File

@ -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:

8
fs/xattr.c
View File

@ -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);

15
include/linux/audit.h
View File

@ -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)

8
ipc/mqueue.c
View File

@ -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;

1
kernel/audit.h
View File

@ -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,

30
kernel/auditfilter.c
View File

@ -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,

41
kernel/auditsc.c
View File

@ -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