[PATCH v2 07/12] crypto: x86/sm3 - fix possible crash with CFI enabled

Eric Biggers ebiggers at kernel.org
Fri Nov 18 11:44:16 PST 2022


From: Eric Biggers <ebiggers at google.com>

sm3_transform_avx() is called via indirect function calls.  Therefore it
needs 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: ccace936eec7 ("x86: Add types to indirectly called assembly functions")
Acked-by: Peter Zijlstra (Intel) <peterz at infradead.org>
Reviewed-by: Sami Tolvanen <samitolvanen at google.com>
Signed-off-by: Eric Biggers <ebiggers at google.com>
---
 arch/x86/crypto/sm3-avx-asm_64.S | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/crypto/sm3-avx-asm_64.S b/arch/x86/crypto/sm3-avx-asm_64.S
index b12b9efb5ec51..8fc5ac681fd63 100644
--- a/arch/x86/crypto/sm3-avx-asm_64.S
+++ b/arch/x86/crypto/sm3-avx-asm_64.S
@@ -12,6 +12,7 @@
  */
 
 #include <linux/linkage.h>
+#include <linux/cfi_types.h>
 #include <asm/frame.h>
 
 /* Context structure */
@@ -328,7 +329,7 @@
  *                        const u8 *data, int nblocks);
  */
 .align 16
-SYM_FUNC_START(sm3_transform_avx)
+SYM_TYPED_FUNC_START(sm3_transform_avx)
 	/* input:
 	 *	%rdi: ctx, CTX
 	 *	%rsi: data (64*nblks bytes)
-- 
2.38.1




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