Re: general protection fault in af_alg_free_areq_sgls

From: Herbert Xu
Date: Wed Nov 29 2017 - 00:24:21 EST


On Tue, Nov 28, 2017 at 01:02:52AM -0800, Eric Biggers wrote:
>
> >From 1a7a7f86f09c50652f1fff75b8d3a32712826b32 Mon Sep 17 00:00:00 2001
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
> Date: Tue, 28 Nov 2017 00:46:24 -0800
> Subject: [PATCH] crypto: af_alg - fix NULL pointer dereference in
> af_alg_free_areq_sgls()
>
> If allocating the ->tsgl member of 'struct af_alg_async_req' failed,
> during cleanup we dereferenced the NULL ->tsgl pointer in
> af_alg_free_areq_sgls(), because ->tsgl_entries was nonzero.
>
> Fix it by only freeing the ->tsgl list if it is non-NULL.
>
> This affected both algif_skcipher and algif_aead.
>
> Fixes: e870456d8e7c ("crypto: algif_skcipher - overhaul memory management")
> Fixes: d887c52d6ae4 ("crypto: algif_aead - overhaul memory management")
> Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
> Cc: <stable@xxxxxxxxxxxxxxx> # v4.14+
> Signed-off-by: Eric Biggers <ebiggers@xxxxxxxxxx>

Patch applied. Thanks.
--
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
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