[PATCH 1/2] aio: prevent double free in ioctx_alloc

[Sasha Levin]

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@xxxxxxxxxx>
---
 fs/aio.c |    1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/aio.c b/fs/aio.c
index 699f53e..8b387a1 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);
-- 
1.7.10.4

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