fanotify: do not dereference inode_mark when it is unset

The fanotify code is supposed to get the group from the mark.  It accidentally
only used the inode_mark.  If the vfsmount_mark was set but not the inode_mark
it would deref the NULL inode_mark.  Get the group from the correct place.

Reported-by: Tvrtko Ursulin <tvrtko.ursulin@sophos.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
This commit is contained in:
Eric Paris 2010-08-18 12:25:49 -04:00
parent 3dc8d7f07e
commit faa9560ae7

View File

@ -148,13 +148,14 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
const unsigned char *file_name,
struct fsnotify_event **event)
{
struct fsnotify_group *group = inode_mark->group;
struct fsnotify_group *group = NULL;
__u32 inode_test_mask = (mask & ~FS_EVENT_ON_CHILD);
__u32 vfsmount_test_mask = (mask & ~FS_EVENT_ON_CHILD);
pr_debug("%s: group=%p to_tell=%p mnt=%p mark=%p mask=%x data=%p"
" data_is=%d cookie=%d event=%p\n", __func__, group, to_tell,
mnt, inode_mark, mask, data, data_is, cookie, *event);
if (unlikely(!inode_mark && !vfsmount_mark)) {
BUG();
return 0;
}
/* clear ignored on inode modification */
if (mask & FS_MODIFY) {
@ -168,18 +169,24 @@ static int send_to_group(struct inode *to_tell, struct vfsmount *mnt,
/* does the inode mark tell us to do something? */
if (inode_mark) {
group = inode_mark->group;
inode_test_mask &= inode_mark->mask;
inode_test_mask &= ~inode_mark->ignored_mask;
}
/* does the vfsmount_mark tell us to do something? */
if (vfsmount_mark) {
group = vfsmount_mark->group;
vfsmount_test_mask &= vfsmount_mark->mask;
vfsmount_test_mask &= ~vfsmount_mark->ignored_mask;
if (inode_mark)
vfsmount_test_mask &= ~inode_mark->ignored_mask;
}
pr_debug("%s: group=%p to_tell=%p mnt=%p mark=%p mask=%x data=%p"
" data_is=%d cookie=%d event=%p\n", __func__, group, to_tell,
mnt, inode_mark, mask, data, data_is, cookie, *event);
if (!inode_test_mask && !vfsmount_test_mask)
return 0;