[PATCH -mm][AIO] Fix AIO completion signal notification possible ref leak

["Sébastien Dugué" <sebastien.dugue@bull.net>]

  Andrew,

  here is an incremental patch to fix a possible ref leak when users
do weird things with the ->sigev_notify flags.

  Thanks Oleg for spotting this.

  Sébastien.


From: Sébastien Dugué <sebastien.dugue@bull.net>

         Fix AIO completion signal notification possible ref leak

  Make sure we only accept valid sigev_notify values in aio_setup_sigevent(),
namely SIGEV_NONE, SIGEV_THREAD_ID or SIGEV_SIGNAL.

 aio.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

Signed-off-by: Sébastien Dugué <sebastien.dugue@bull.net>


Index: linux-2.6.20-rc6-mm3/fs/aio.c
===================================================================
--- linux-2.6.20-rc6-mm3.orig/fs/aio.c	2007-02-05 16:50:27.000000000 +0100
+++ linux-2.6.20-rc6-mm3/fs/aio.c	2007-02-05 16:53:43.000000000 +0100
@@ -939,7 +939,7 @@ static int aio_send_signal(struct aio_no
 	info->si_uid = 0;
 	info->si_value = notify->value;
 
-	if (notify->notify & SIGEV_THREAD_ID)
+	if (notify->notify == SIGEV_THREAD_ID)
 		ret = send_sigqueue(notify->signo, sigq, notify->target);
 	else
 		ret = send_group_sigqueue(notify->signo, sigq, notify->target);
@@ -959,6 +959,10 @@ static long aio_setup_sigevent(struct ai
 	if (event.sigev_notify == SIGEV_NONE)
 		return 0;
 
+	if (event.sigev_notify != SIGEV_SIGNAL &&
+	    event.sigev_notify != SIGEV_THREAD_ID)
+		return -EINVAL;
+
 	notify->notify = event.sigev_notify;
 	notify->signo = event.sigev_signo;
 	notify->value = event.sigev_value;