Linux cryptographic layer development
 help / color / mirror / Atom feed
* [PATCH] crypto: ccree - use crypto_memneq() to compare AEAD tag
@ 2026-08-15 17:09 David C.C.M. Gall
  0 siblings, 0 replies; only message in thread
From: David C.C.M. Gall @ 2026-08-15 17:09 UTC (permalink / raw)
  To: Gilad Ben-Yossef, Herbert Xu, David S. Miller, linux-crypto,
	linux-kernel
  Cc: gregkh

cc_aead_complete() compares the computed MAC against the received ICV
with memcmp(), which short-circuits on the first differing byte and
leaks tag-match length via timing. Use crypto_memneq() instead.

Assisted-by: gregkh_clanker_t1000
Signed-off-by: David C.C.M. Gall <david.ccm.gall@googlemail.com>
---
 drivers/crypto/ccree/cc_aead.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/ccree/cc_aead.c b/drivers/crypto/ccree/cc_aead.c
index 088c4603047f..d57a98f89e53 100644
--- a/drivers/crypto/ccree/cc_aead.c
+++ b/drivers/crypto/ccree/cc_aead.c
@@ -226,8 +226,8 @@ static void cc_aead_complete(struct device *dev, void *cc_req, int err)
 		goto done;
 
 	if (areq_ctx->gen_ctx.op_type == DRV_CRYPTO_DIRECTION_DECRYPT) {
-		if (memcmp(areq_ctx->mac_buf, areq_ctx->icv_virt_addr,
-			   ctx->authsize) != 0) {
+		if (crypto_memneq(areq_ctx->mac_buf, areq_ctx->icv_virt_addr,
+				  ctx->authsize)) {
 			dev_dbg(dev, "Payload authentication failure, (auth-size=%d, cipher=%d)\n",
 				ctx->authsize, ctx->cipher_mode);
 			/* In case of payload authentication failure, MUST NOT
-- 
2.43.0


^ permalink raw reply related	[flat|nested] only message in thread

only message in thread, other threads:[~2026-08-15 17:10 UTC | newest]

Thread overview: (only message) (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-08-15 17:09 [PATCH] crypto: ccree - use crypto_memneq() to compare AEAD tag David C.C.M. Gall

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox