[PATCH 5.4 247/320] crypto: stm32/crc32 - Fix kernel BUG triggered in probe()

Greg Kroah-Hartman
2022-01-24T19:41:07Z

From: Marek Vasut <marex@denx.de>

commit 29009604ad4e3ef784fd9b9fef6f23610ddf633d upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/crypto/stm32/stm32-crc32.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- 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,