From faa9560ae76ef50a3cbfb1a6afc0343fd8172374 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Wed, 18 Aug 2010 12:25:49 -0400 Subject: [PATCH] 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 Signed-off-by: Eric Paris --- fs/notify/fsnotify.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index 3970392b2722..f3e3b355ba7f 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -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;