diff options
Diffstat (limited to 'target/linux/generic/backport-5.4/080-wireguard-0103-wireguard-noise-read-preshared-key-while-taking-lock.patch')
| -rw-r--r-- | target/linux/generic/backport-5.4/080-wireguard-0103-wireguard-noise-read-preshared-key-while-taking-lock.patch | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/target/linux/generic/backport-5.4/080-wireguard-0103-wireguard-noise-read-preshared-key-while-taking-lock.patch b/target/linux/generic/backport-5.4/080-wireguard-0103-wireguard-noise-read-preshared-key-while-taking-lock.patch new file mode 100644 index 0000000000..2dac4b7064 --- /dev/null +++ b/target/linux/generic/backport-5.4/080-wireguard-0103-wireguard-noise-read-preshared-key-while-taking-lock.patch @@ -0,0 +1,61 @@ +From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 +From: "Jason A. Donenfeld" <Jason@zx2c4.com> +Date: Tue, 19 May 2020 22:49:28 -0600 +Subject: [PATCH] wireguard: noise: read preshared key while taking lock + +commit bc67d371256f5c47d824e2eec51e46c8d62d022e upstream. + +Prior we read the preshared key after dropping the handshake lock, which +isn't an actual crypto issue if it races, but it's still not quite +correct. So copy that part of the state into a temporary like we do with +the rest of the handshake state variables. Then we can release the lock, +operate on the temporary, and zero it out at the end of the function. In +performance tests, the impact of this was entirely unnoticable, probably +because those bytes are coming from the same cacheline as other things +that are being copied out in the same manner. + +Reported-by: Matt Dunwoodie <ncon@noconroy.net> +Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") +Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> +--- + drivers/net/wireguard/noise.c | 6 +++++- + 1 file changed, 5 insertions(+), 1 deletion(-) + +--- a/drivers/net/wireguard/noise.c ++++ b/drivers/net/wireguard/noise.c +@@ -715,6 +715,7 @@ wg_noise_handshake_consume_response(stru + u8 e[NOISE_PUBLIC_KEY_LEN]; + u8 ephemeral_private[NOISE_PUBLIC_KEY_LEN]; + u8 static_private[NOISE_PUBLIC_KEY_LEN]; ++ u8 preshared_key[NOISE_SYMMETRIC_KEY_LEN]; + + down_read(&wg->static_identity.lock); + +@@ -733,6 +734,8 @@ wg_noise_handshake_consume_response(stru + memcpy(chaining_key, handshake->chaining_key, NOISE_HASH_LEN); + memcpy(ephemeral_private, handshake->ephemeral_private, + NOISE_PUBLIC_KEY_LEN); ++ memcpy(preshared_key, handshake->preshared_key, ++ NOISE_SYMMETRIC_KEY_LEN); + up_read(&handshake->lock); + + if (state != HANDSHAKE_CREATED_INITIATION) +@@ -750,7 +753,7 @@ wg_noise_handshake_consume_response(stru + goto fail; + + /* psk */ +- mix_psk(chaining_key, hash, key, handshake->preshared_key); ++ mix_psk(chaining_key, hash, key, preshared_key); + + /* {} */ + if (!message_decrypt(NULL, src->encrypted_nothing, +@@ -783,6 +786,7 @@ out: + memzero_explicit(chaining_key, NOISE_HASH_LEN); + memzero_explicit(ephemeral_private, NOISE_PUBLIC_KEY_LEN); + memzero_explicit(static_private, NOISE_PUBLIC_KEY_LEN); ++ memzero_explicit(preshared_key, NOISE_SYMMETRIC_KEY_LEN); + up_read(&wg->static_identity.lock); + return ret_peer; + } |