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authorCfir Cohen2019-07-02 10:32:56 -0700
committerHerbert Xu2019-07-18 13:39:54 +0800
commit538a5a072e6ef04377b180ee9b3ce5bae0a85da4 (patch)
tree7aed90b4c1ecb0291a9d17523d4bc87fec505b44 /drivers
parent20e833dc36355ed642d00067641a679c618303fa (diff)
crypto: ccp/gcm - use const time tag comparison.
Avoid leaking GCM tag through timing side channel. Fixes: 36cf515b9bbe ("crypto: ccp - Enable support for AES GCM on v5 CCPs") Cc: <stable@vger.kernel.org> # v4.12+ Signed-off-by: Cfir Cohen <cfir@google.com> Acked-by: Gary R Hook <ghook@amd.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/crypto/ccp/ccp-ops.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/crypto/ccp/ccp-ops.c b/drivers/crypto/ccp/ccp-ops.c
index 9ecc1bb4b237..3ebe031773d5 100644
--- a/drivers/crypto/ccp/ccp-ops.c
+++ b/drivers/crypto/ccp/ccp-ops.c
@@ -850,7 +850,8 @@ static int ccp_run_aes_gcm_cmd(struct ccp_cmd_queue *cmd_q,
if (ret)
goto e_tag;
- ret = memcmp(tag.address, final_wa.address, AES_BLOCK_SIZE);
+ ret = crypto_memneq(tag.address, final_wa.address,
+ AES_BLOCK_SIZE) ? -EBADMSG : 0;
ccp_dm_free(&tag);
}