Date:   Fri, 31 Dec 2021 22:34:42 +1100
From:   Herbert Xu <herbert@gondor.apana.org.au>
To:     Marek Vasut <marex@denx.de>
Cc:     linux-crypto@vger.kernel.org, stable@vger.kernel.org,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        Fabien Dessenne <fabien.dessenne@st.com>,
        Lionel Debieve <lionel.debieve@st.com>,
        Nicolas Toromanoff <nicolas.toromanoff@st.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-stm32@st-md-mailman.stormreply.com
Subject: Re: [PATCH] crypto: stm32/crc32 - Fix kernel BUG triggered in probe()
Message-ID: <Yc7q0o1HL2THW2Kc@gondor.apana.org.au>
References: <20211220195022.1387104-1-marex@denx.de>
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On Mon, Dec 20, 2021 at 08:50:22PM +0100, Marek Vasut wrote:
> The include/linux/crypto.h struct crypto_alg field cra_driver_name description
> states "Unique name of the transformation provider. " ... " this contains the
> name of the chip or provider and the name of the transformation algorithm."
> 
> In case of the stm32-crc driver, field cra_driver_name is identical for all
> registered transformation providers and set to the name of the driver itself,
> which is incorrect. This patch fixes it by assigning a unique cra_driver_name
> to each registered transformation provider.
> 
> The kernel crash is triggered when the driver calls crypto_register_shashes()
> which calls crypto_register_shash(), which calls crypto_register_alg(), which
> calls __crypto_register_alg(), which returns -EEXIST, which is propagated
> back through this call chain. Upon -EEXIST from crypto_register_shash(), the
> crypto_register_shashes() starts unregistering the providers back, and calls
> crypto_unregister_shash(), which calls crypto_unregister_alg(), and this is
> where the BUG() triggers due to incorrect cra_refcnt.
> 
> Fixes: b51dbe90912a ("crypto: stm32 - Support for STM32 CRC32 crypto module")
> Signed-off-by: Marek Vasut <marex@denx.de>
> Cc: <stable@vger.kernel.org> # 4.12+
> Cc: Alexandre Torgue <alexandre.torgue@foss.st.com>
> Cc: Fabien Dessenne <fabien.dessenne@st.com>
> Cc: Herbert Xu <herbert@gondor.apana.org.au>
> Cc: Lionel Debieve <lionel.debieve@st.com>
> Cc: Nicolas Toromanoff <nicolas.toromanoff@st.com>
> Cc: linux-arm-kernel@lists.infradead.org
> Cc: linux-stm32@st-md-mailman.stormreply.com
> To: linux-crypto@vger.kernel.org
> ---
>  drivers/crypto/stm32/stm32-crc32.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

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