Subject: Re: [PATCH] crypto: qce: fix uaf on qce_skcipher_register_one
To:     Chengfeng Ye <cyeaa@connect.ust.hk>, herbert@gondor.apana.org.au,
        davem@davemloft.net, svarbanov@mm-sol.com
Cc:     linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
        linux-arm-msm@vger.kernel.org
References: <20211104134642.20638-1-cyeaa@connect.ust.hk>
From:   Thara Gopinath <thara.gopinath@linaro.org>
Message-ID: <7a158429-6eed-bbcb-f4d0-a6db8ba40d58@linaro.org>
Date:   Fri, 5 Nov 2021 17:12:04 -0400
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On 11/4/21 9:46 AM, Chengfeng Ye wrote:
> Pointer alg points to sub field of tmpl, it
> is dereferenced after tmpl is freed. Fix
> this by accessing alg before free tmpl.
> 
> Fixes: ec8f5d8f ("crypto: qce - Qualcomm crypto engine driver")
> Signed-off-by: Chengfeng Ye <cyeaa@connect.ust.hk>

Acked-by: Thara Gopinath <thara.gopinath@linaro.org>

> ---
>   drivers/crypto/qce/skcipher.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/crypto/qce/skcipher.c b/drivers/crypto/qce/skcipher.c
> index 8ff10928f581..3d27cd5210ef 100644
> --- a/drivers/crypto/qce/skcipher.c
> +++ b/drivers/crypto/qce/skcipher.c
> @@ -484,8 +484,8 @@ static int qce_skcipher_register_one(const struct qce_skcipher_def *def,
>   
>   	ret = crypto_register_skcipher(alg);
>   	if (ret) {
> -		kfree(tmpl);
>   		dev_err(qce->dev, "%s registration failed\n", alg->base.cra_name);
> +		kfree(tmpl);
>   		return ret;
>   	}
>   
> 

-- 
Warm Regards
Thara (She/Her/Hers)