From: Sasha Levin <sasha.levin@oracle.com>
Date: Tue, 19 Nov 2013 22:33:02 +0000 (-0500)
Subject: aio: prevent double free in ioctx_alloc
X-Git-Tag: v3.12.4~5
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f50db974cb75e31d98b176c3c9ea92e57aa97a1b;p=kernel%2Fkernel-generic.git

aio: prevent double free in ioctx_alloc

commit d558023207e008a4476a3b7bb8706b2a2bf5d84f upstream.

ioctx_alloc() calls aio_setup_ring() to allocate a ring. If aio_setup_ring()
fails to do so it would call aio_free_ring() before returning, but
ioctx_alloc() would call aio_free_ring() again causing a double free of
the ring.

This is easily reproducible from userspace.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Benjamin LaHaise <bcrl@kvack.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/aio.c b/fs/aio.c
index fff5db0..f4103b3 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -661,7 +661,6 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
 err_cleanup:
 	aio_nr_sub(ctx->max_reqs);
 err:
-	aio_free_ring(ctx);
 	free_percpu(ctx->cpu);
 	free_percpu(ctx->reqs.pcpu_count);
 	free_percpu(ctx->users.pcpu_count);