[PATCH] crypto: arm64/ghash - Fix incorrect output from ghash-neon

[Eric Biggers]

Commit 9a7c987fb92b ("crypto: arm64/ghash - Use API partial block
handling") made ghash_finup() pass the wrong buffer to
ghash_do_simd_update().  As a result, ghash-neon now produces incorrect
outputs when the message length isn't divisible by 16 bytes.  Fix this.

(I didn't notice this earlier because this code is reached only on CPUs
that support NEON but not PMULL.  I haven't yet found a way to get
qemu-system-aarch64 to emulate that configuration.)

Fixes: 9a7c987fb92b ("crypto: arm64/ghash - Use API partial block handling")
Cc: stable at vger.kernel.org
Reported-by: Diederik de Haas <diederik at cknow-tech.com>
Closes: https://lore.kernel.org/linux-crypto/DETXT7QI62KE.F3CGH2VWX1SC@cknow-tech.com/
Signed-off-by: Eric Biggers <ebiggers at kernel.org>
---

If it's okay, I'd like to just take this via libcrypto-fixes.

 arch/arm64/crypto/ghash-ce-glue.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c
index 7951557a285a..ef249d06c92c 100644
--- a/arch/arm64/crypto/ghash-ce-glue.c
+++ b/arch/arm64/crypto/ghash-ce-glue.c
@@ -131,11 +131,11 @@ static int ghash_finup(struct shash_desc *desc, const u8 *src,
 
 	if (len) {
 		u8 buf[GHASH_BLOCK_SIZE] = {};
 
 		memcpy(buf, src, len);
-		ghash_do_simd_update(1, ctx->digest, src, key, NULL,
+		ghash_do_simd_update(1, ctx->digest, buf, key, NULL,
 				     pmull_ghash_update_p8);
 		memzero_explicit(buf, sizeof(buf));
 	}
 	return ghash_export(desc, dst);
 }

base-commit: 7a3984bbd69055898add0fe22445f99435f33450
-- 
2.52.0