diff mbox series

crypto: stm32/crc32 - Fix kernel BUG triggered in probe()

Message ID 20220123162240.5532-1-marex@denx.de (mailing list archive)
State New, archived
Headers show
Series crypto: stm32/crc32 - Fix kernel BUG triggered in probe() | expand

Commit Message

Marek Vasut Jan. 23, 2022, 4:22 p.m. UTC
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
Acked-by: Nicolas Toromanoff <nicolas.toromanoff@foss.st.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
---
Backport on 4.19.225, likely works on 4.14 too.
The patch likely failed to apply because the hit 5.3:
fdbd643a74efb ("crypto: stm32/crc32 - rename driver file")
and renamed drivers/crypto/stm32/stm32{-,_}crc32.c
---
 drivers/crypto/stm32/stm32_crc32.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Greg KH Jan. 24, 2022, 9:41 a.m. UTC | #1
On Sun, Jan 23, 2022 at 05:22:40PM +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
> Acked-by: Nicolas Toromanoff <nicolas.toromanoff@foss.st.com>
> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
> ---
> Backport on 4.19.225, likely works on 4.14 too.
> The patch likely failed to apply because the hit 5.3:
> fdbd643a74efb ("crypto: stm32/crc32 - rename driver file")
> and renamed drivers/crypto/stm32/stm32{-,_}crc32.c
> ---
>  drivers/crypto/stm32/stm32_crc32.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)

Now queued up, thanks.

greg k-h
diff mbox series

Patch

diff --git a/drivers/crypto/stm32/stm32_crc32.c b/drivers/crypto/stm32/stm32_crc32.c
index 47d31335c2d42..6848f34a9e66a 100644
--- a/drivers/crypto/stm32/stm32_crc32.c
+++ b/drivers/crypto/stm32/stm32_crc32.c
@@ -230,7 +230,7 @@  static struct shash_alg algs[] = {
 		.digestsize     = CHKSUM_DIGEST_SIZE,
 		.base           = {
 			.cra_name               = "crc32",
-			.cra_driver_name        = DRIVER_NAME,
+			.cra_driver_name        = "stm32-crc32-crc32",
 			.cra_priority           = 200,
 			.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
 			.cra_blocksize          = CHKSUM_BLOCK_SIZE,
@@ -252,7 +252,7 @@  static struct shash_alg algs[] = {
 		.digestsize     = CHKSUM_DIGEST_SIZE,
 		.base           = {
 			.cra_name               = "crc32c",
-			.cra_driver_name        = DRIVER_NAME,
+			.cra_driver_name        = "stm32-crc32-crc32c",
 			.cra_priority           = 200,
 			.cra_flags		= CRYPTO_ALG_OPTIONAL_KEY,
 			.cra_blocksize          = CHKSUM_BLOCK_SIZE,