[PATCH] crypto: arm64/sm4 - fix possible crash with CFI enabled

[PATCH] crypto: arm64/sm4 - fix possible crash with CFI enabled

[Tianjia Zhang]

The SM4 CCM/GCM assembly functions for encryption and decryption is
called via indirect function calls.  Therefore they need to use
SYM_TYPED_FUNC_START instead of SYM_FUNC_START to cause its type hash
to be emitted when the kernel is built with CONFIG_CFI_CLANG=y.
Otherwise, the code crashes with a CFI failure (if the compiler didn't
happen to optimize out the indirect call).

Fixes: 67fa3a7fdf80 ("crypto: arm64/sm4 - add CE implementation for CCM mode")
Fixes: ae1b83c7d572 ("crypto: arm64/sm4 - add CE implementation for GCM mode")
Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
---
 arch/arm64/crypto/sm4-ce-ccm-core.S | 5 +++--
 arch/arm64/crypto/sm4-ce-gcm-core.S | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/crypto/sm4-ce-ccm-core.S b/arch/arm64/crypto/sm4-ce-ccm-core.S
index 028207c4afd0..fa85856f33ce 100644
--- a/arch/arm64/crypto/sm4-ce-ccm-core.S
+++ b/arch/arm64/crypto/sm4-ce-ccm-core.S
@@ -8,6 +8,7 @@
  */
 
 #include <linux/linkage.h>
+#include <linux/cfi_types.h>
 #include <asm/assembler.h>
 #include "sm4-ce-asm.h"
 
@@ -104,7 +105,7 @@ SYM_FUNC_START(sm4_ce_ccm_final)
 SYM_FUNC_END(sm4_ce_ccm_final)
 
 .align 3
-SYM_FUNC_START(sm4_ce_ccm_enc)
+SYM_TYPED_FUNC_START(sm4_ce_ccm_enc)
 	/* input:
 	 *   x0: round key array, CTX
 	 *   x1: dst
@@ -216,7 +217,7 @@ SYM_FUNC_START(sm4_ce_ccm_enc)
 SYM_FUNC_END(sm4_ce_ccm_enc)
 
 .align 3
-SYM_FUNC_START(sm4_ce_ccm_dec)
+SYM_TYPED_FUNC_START(sm4_ce_ccm_dec)
 	/* input:
 	 *   x0: round key array, CTX
 	 *   x1: dst
diff --git a/arch/arm64/crypto/sm4-ce-gcm-core.S b/arch/arm64/crypto/sm4-ce-gcm-core.S
index 7aa3ec18a289..347f25d75727 100644
--- a/arch/arm64/crypto/sm4-ce-gcm-core.S
+++ b/arch/arm64/crypto/sm4-ce-gcm-core.S
@@ -9,6 +9,7 @@
  */
 
 #include <linux/linkage.h>
+#include <linux/cfi_types.h>
 #include <asm/assembler.h>
 #include "sm4-ce-asm.h"
 
@@ -370,7 +371,7 @@ SYM_FUNC_START(pmull_ghash_update)
 SYM_FUNC_END(pmull_ghash_update)
 
 .align 3
-SYM_FUNC_START(sm4_ce_pmull_gcm_enc)
+SYM_TYPED_FUNC_START(sm4_ce_pmull_gcm_enc)
 	/* input:
 	 *   x0: round key array, CTX
 	 *   x1: dst
@@ -581,7 +582,7 @@ SYM_FUNC_END(sm4_ce_pmull_gcm_enc)
 #define	RH3	v20
 
 .align 3
-SYM_FUNC_START(sm4_ce_pmull_gcm_dec)
+SYM_TYPED_FUNC_START(sm4_ce_pmull_gcm_dec)
 	/* input:
 	 *   x0: round key array, CTX
 	 *   x1: dst
-- 
2.24.3 (Apple Git-128)

Re: [PATCH] crypto: arm64/sm4 - fix possible crash with CFI enabled

[Herbert Xu]

On Wed, Dec 21, 2022 at 03:32:32PM +0800, Tianjia Zhang wrote:
> The SM4 CCM/GCM assembly functions for encryption and decryption is
> called via indirect function calls.  Therefore they need to use
> SYM_TYPED_FUNC_START instead of SYM_FUNC_START to cause its type hash
> to be emitted when the kernel is built with CONFIG_CFI_CLANG=y.
> Otherwise, the code crashes with a CFI failure (if the compiler didn't
> happen to optimize out the indirect call).
> 
> Fixes: 67fa3a7fdf80 ("crypto: arm64/sm4 - add CE implementation for CCM mode")
> Fixes: ae1b83c7d572 ("crypto: arm64/sm4 - add CE implementation for GCM mode")
> Signed-off-by: Tianjia Zhang <tianjia.zhang@linux.alibaba.com>
> ---
>  arch/arm64/crypto/sm4-ce-ccm-core.S | 5 +++--
>  arch/arm64/crypto/sm4-ce-gcm-core.S | 5 +++--
>  2 files changed, 6 insertions(+), 4 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