FAILED: patch "[PATCH] crypto: stm32/crc32 - Fix kernel BUG triggered in probe()" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 29009604ad4e3ef784fd9b9fef6f23610ddf633d Mon Sep 17 00:00:00 2001
From: Marek Vasut <[email protected]>
Date: Mon, 20 Dec 2021 20:50:22 +0100
Subject: [PATCH] crypto: stm32/crc32 - Fix kernel BUG triggered in probe()

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.

To: [email protected]

index 75867c0b0017..be1bf39a317d 100644
@@ -279,7 +279,7 @@ 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,

@@ -301,7 +301,7 @@ 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,

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.

To: [email protected]

---
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(-)

index 47d31335c2d42..6848f34a9e66a 100644
@@ -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,

2.34.1

Now queued up, thanks.

greg k-h