[PATCH resend] audit: fix mark refcounting

From: Miklos Szeredi
Date: Wed Dec 14 2011 - 09:36:08 EST


I think this should go into 3.2 (and stable).

Please apply.

Thanks,
Miklos
----

From: Miklos Szeredi <mszeredi@xxxxxxx>
Subject: audit: fix mark refcounting

Removing the parent of a watched file results in "kernel BUG at
fs/notify/mark.c:139".

To reproduce

add "-w /tmp/audit/dir/watched_file" to audit.rules
rm -rf /tmp/audit/dir

This is caused by fsnotify_destroy_mark() being called without an
extra reference taken by the caller.

Reported by Francesco Cosoleto here:

https://bugzilla.novell.com/show_bug.cgi?id=689860

Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxx>
CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
CC: Eric Paris <eparis@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx
---
kernel/audit_watch.c | 2 ++
1 file changed, 2 insertions(+)

Index: linux.git/kernel/audit_watch.c
===================================================================
--- linux.git.orig/kernel/audit_watch.c 2011-12-06 16:39:48.000000000 +0100
+++ linux.git/kernel/audit_watch.c 2011-12-13 14:05:37.000000000 +0100
@@ -349,7 +349,9 @@ static void audit_remove_parent_watches(
}
mutex_unlock(&audit_filter_mutex);

+ audit_get_parent(parent);
fsnotify_destroy_mark(&parent->mark);
+ audit_put_parent(parent);
}

/* Get path information necessary for adding watches. */
--
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