diff options
| author | Eric Biggers <ebiggers@kernel.org> | 2026-03-02 12:36:00 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-03 17:16:54 -0800 |
| commit | 67edfec516d30d3e62925c397be4a1e5185802fc (patch) | |
| tree | ee4b94f898a13828185543d5644550203d1430d0 | |
| parent | 2ffb4f5c2ccb2fa1c049dd11899aee7967deef5a (diff) | |
net/tcp-ao: Fix MAC comparison to be constant-time
To prevent timing attacks, MACs need to be compared in constant
time. Use the appropriate helper function for this.
Fixes: 0a3a809089eb ("net/tcp: Verify inbound TCP-AO signed segments")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Dmitry Safonov <0x7f454c46@gmail.com>
Link: https://patch.msgid.link/20260302203600.13561-1-ebiggers@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | net/ipv4/Kconfig | 1 | ||||
| -rw-r--r-- | net/ipv4/tcp_ao.c | 3 |
2 files changed, 3 insertions, 1 deletions
diff --git a/net/ipv4/Kconfig b/net/ipv4/Kconfig index b71c22475c51..3ab6247be585 100644 --- a/net/ipv4/Kconfig +++ b/net/ipv4/Kconfig @@ -748,6 +748,7 @@ config TCP_SIGPOOL config TCP_AO bool "TCP: Authentication Option (RFC5925)" select CRYPTO + select CRYPTO_LIB_UTILS select TCP_SIGPOOL depends on 64BIT && IPV6 != m # seq-number extension needs WRITE_ONCE(u64) help diff --git a/net/ipv4/tcp_ao.c b/net/ipv4/tcp_ao.c index 4980caddb0fc..a97cdf3e6af4 100644 --- a/net/ipv4/tcp_ao.c +++ b/net/ipv4/tcp_ao.c @@ -10,6 +10,7 @@ #define pr_fmt(fmt) "TCP: " fmt #include <crypto/hash.h> +#include <crypto/utils.h> #include <linux/inetdevice.h> #include <linux/tcp.h> @@ -922,7 +923,7 @@ tcp_ao_verify_hash(const struct sock *sk, const struct sk_buff *skb, /* XXX: make it per-AF callback? */ tcp_ao_hash_skb(family, hash_buf, key, sk, skb, traffic_key, (phash - (u8 *)th), sne); - if (memcmp(phash, hash_buf, maclen)) { + if (crypto_memneq(phash, hash_buf, maclen)) { NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPAOBAD); atomic64_inc(&info->counters.pkt_bad); atomic64_inc(&key->pkt_bad); |