[Linux-stm32] [PATCH] crypto: stm32/crc32 - Fix kernel BUG triggered in probe()

[Nicolas Toromanoff]

On Mon, 20 Dec 2021, 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 at denx.de>
> Cc: <stable at vger.kernel.org> # 4.12+
> Cc: Alexandre Torgue <alexandre.torgue at foss.st.com>
> Cc: Fabien Dessenne <fabien.dessenne at st.com>
> Cc: Herbert Xu <herbert at gondor.apana.org.au>
> Cc: Lionel Debieve <lionel.debieve at st.com>
> Cc: Nicolas Toromanoff <nicolas.toromanoff at st.com>
> Cc: linux-arm-kernel at lists.infradead.org
> Cc: linux-stm32 at st-md-mailman.stormreply.com
> To: linux-crypto at vger.kernel.org
> ---
> drivers/crypto/stm32/stm32-crc32.c | 4 ++--

Hello Marek,

Thanks for the fix.

Acked-by: Nicolas Toromanoff <nicolas.toromanoff at foss.st.com>