The patch titled
fix race in inotify_release
has been added to the -mm tree. Its filename is
fix-race-in-inotify_release.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: Amy Griffis <amy.griffis@xxxxxx>
While doing some inotify stress testing, I hit the following race. In
inotify_release(), it's possible for a watch to be removed from the lists
in between dropping dev->mutex and taking inode->inotify_mutex. The
reference we hold prevents the watch from being freed, but not from being
removed.
Checking the dev's idr mapping will prevent a double list_del of the
same watch.
Signed-off-by: Amy Griffis <amy.griffis@xxxxxx>
Acked-by: John McCutchan <john@xxxxxxxxxxxxxxxxx>
Cc: Robert Love <rml@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
fs/inotify.c | 6 +++++-
1 files changed, 5 insertions(+), 1 deletion(-)
diff -puN fs/inotify.c~fix-race-in-inotify_release fs/inotify.c
--- 25/fs/inotify.c~fix-race-in-inotify_release Tue May 16 13:55:58 2006
+++ 25-akpm/fs/inotify.c Tue May 16 13:55:58 2006
@@ -848,7 +848,11 @@ static int inotify_release(struct inode
inode = watch->inode;
mutex_lock(&inode->inotify_mutex);
mutex_lock(&dev->mutex);
- remove_watch_no_event(watch, dev);
+
+ /* make sure we didn't race with another list removal */
+ if (likely(idr_find(&dev->idr, watch->wd)))
+ remove_watch_no_event(watch, dev);
+
mutex_unlock(&dev->mutex);
mutex_unlock(&inode->inotify_mutex);
put_inotify_watch(watch);
_
Patches currently in -mm which might be from amy.griffis@xxxxxx are
fix-race-in-inotify_release.patch
-
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