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| author | Eric Paris <eparis@redhat.com> | 2009-07-07 10:28:23 -0400 |
|---|---|---|
| committer | Eric Paris <eparis@redhat.com> | 2009-07-21 15:26:26 -0400 |
| commit | 75fe2b26394c59c8e16bd7b76f4be5d048103ad1 (patch) | |
| tree | 0f2a6c59dd1c6eddc497b9c7363298e949c0768a /fs/notify | |
| parent | 5549f7cdf84c02939fd368d0842aa2f472bb6e98 (diff) | |
| download | linux-75fe2b26394c59c8e16bd7b76f4be5d048103ad1.tar.gz linux-75fe2b26394c59c8e16bd7b76f4be5d048103ad1.tar.bz2 linux-75fe2b26394c59c8e16bd7b76f4be5d048103ad1.zip | |
inotify: do not leak inode marks in inotify_add_watch
inotify_add_watch had a couple of problems. The biggest being that if
inotify_add_watch was called on the same inode twice (to update or change the
event mask) a refence was taken on the original inode mark by
fsnotify_find_mark_entry but was not being dropped at the end of the
inotify_add_watch call. Thus if inotify_rm_watch was called although the mark
was removed from the inode, the refcnt wouldn't hit zero and we would leak
memory.
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/inotify/inotify_user.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c index 1a870f9157b3..aff4214f16c3 100644 --- a/fs/notify/inotify/inotify_user.c +++ b/fs/notify/inotify/inotify_user.c @@ -463,9 +463,6 @@ retry: goto out_err; spin_lock(&group->inotify_data.idr_lock); - /* if entry is added to the idr we keep the reference obtained - * through fsnotify_mark_add. remember to drop this reference - * when entry is removed from idr */ ret = idr_get_new_above(&group->inotify_data.idr, entry, ++group->inotify_data.last_wd, &ientry->wd); @@ -476,8 +473,13 @@ retry: goto out_err; } atomic_inc(&group->inotify_data.user->inotify_watches); + + /* we put the mark on the idr, take a reference */ + fsnotify_get_mark(entry); } + ret = ientry->wd; + spin_lock(&entry->lock); old_mask = entry->mask; @@ -508,7 +510,11 @@ retry: fsnotify_recalc_group_mask(group); } - return ientry->wd; + /* this either matches fsnotify_find_mark_entry, or init_mark_entry + * depending on which path we took... */ + fsnotify_put_mark(entry); + + return ret; out_err: /* see this isn't supposed to happen, just kill the watch */ |