Otherwise, we enable a MAC forgery via timing attack. Signed-off-by: Jason A. Donenfeld <Jason@xxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: netdev@xxxxxxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx --- net/ipv6/seg6_hmac.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c index f950cb53d5e3..54213c83b44e 100644 --- a/net/ipv6/seg6_hmac.c +++ b/net/ipv6/seg6_hmac.c @@ -38,6 +38,7 @@ #include <net/xfrm.h> #include <linux/cryptohash.h> +#include <crypto/algapi.h> #include <crypto/hash.h> #include <crypto/sha.h> #include <net/seg6.h> @@ -274,7 +275,7 @@ bool seg6_hmac_validate_skb(struct sk_buff *skb) if (seg6_hmac_compute(hinfo, srh, &ipv6_hdr(skb)->saddr, hmac_output)) return false; - if (memcmp(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN) != 0) + if (crypto_memneq(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN)) return false; return true; -- 2.13.1