Re: [PATCH v3] crypto: essiv: fix use-after-free in AEAD path

[Herbert Xu]

On Fri, Oct 16, 2026 at 07:50:31AM +0000, Jérémy Jean wrote:
> The request that ESSIV submits to its wrapped AEAD transform may
> finish before crypto_aead_encrypt() or crypto_aead_decrypt() returns.
> In case this happens, essiv_aead_done() calls aead_request_complete()
> on the original ESSIV request, which can end up freeing the request
> before essiv_aead_crypt() resumes, creating a UAF:
> 
>   BUG: KASAN: slab-use-after-free in essiv_aead_crypt+0x8e6/0x950
>   Read of size 8 at addr ffff888102af1360 by task init/66
> 
> Check the return status before dereferencing rctx after submitting that
> request. If the operation did not return -EINPROGRESS or -EBUSY, then
> the request cannot have been freed yet.
> 
> Fixes: be1eb7f78aa8 ("crypto: essiv - create wrapper template for ESSIV generation")
> Cc: stable@xxxxxxxxxxxxxxx
> Assisted-by: LLM
> Signed-off-by: Jérémy Jean <Jeremy.Jean@xxxxxxxxxxxxxxxxx>
> ---
> 
> Changes in v3:
>  - Code simplification.
> 
> Changes in v2:
>  - Drop the local assoc variable and check the return status before
>    dereferencing rctx, as requested by Herbert Xu.
> 
> v1: https://lore.kernel.org/linux-crypto/20261014222351.2930674-1-Jeremy.Jean@xxxxxxxxxxxxxxxxx/
> v2: https://lore.kernel.org/linux-crypto/20261015121743.3151400-2-Jeremy.Jean@xxxxxxxxxxxxxxxxx/
> 
>  crypto/essiv.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

Patch applied.  Thanks.
-- 
Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Home Page: http://gondor.apana.org.au/~herbert/
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