From 166391159c5deb84795d2ff46e95f276177fa5fb Mon Sep 17 00:00:00 2001 From: YueHaibing Date: Wed, 18 Mar 2020 18:30:43 -0600 Subject: [PATCH 1/5] wireguard: selftests: remove duplicated include This commit removes a duplicated include. Signed-off-by: YueHaibing Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- tools/testing/selftests/wireguard/qemu/init.c | 1 - 1 file changed, 1 deletion(-) diff --git a/tools/testing/selftests/wireguard/qemu/init.c b/tools/testing/selftests/wireguard/qemu/init.c index 90bc9813cadc..c9698120ac9d 100644 --- a/tools/testing/selftests/wireguard/qemu/init.c +++ b/tools/testing/selftests/wireguard/qemu/init.c @@ -13,7 +13,6 @@ #include #include #include -#include #include #include #include From 551599edbfff2431cef943a772fbde1c3e26eaf8 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 18 Mar 2020 18:30:44 -0600 Subject: [PATCH 2/5] wireguard: selftests: test using new 64-bit time_t In case this helps expose bugs with the newer 64-bit time_t types, we do our testing with the newer musl that supports this as well as CONFIG_COMPAT_32BIT_TIME=n. This matters to us, since wireguard does in fact deal with timestamps. Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- tools/testing/selftests/wireguard/qemu/Makefile | 2 +- tools/testing/selftests/wireguard/qemu/kernel.config | 1 - 2 files changed, 1 insertion(+), 2 deletions(-) diff --git a/tools/testing/selftests/wireguard/qemu/Makefile b/tools/testing/selftests/wireguard/qemu/Makefile index 28d477683e8a..90598a425c18 100644 --- a/tools/testing/selftests/wireguard/qemu/Makefile +++ b/tools/testing/selftests/wireguard/qemu/Makefile @@ -41,7 +41,7 @@ $(DISTFILES_PATH)/$(1): flock -x $$@.lock -c '[ -f $$@ ] && exit 0; wget -O $$@.tmp $(MIRROR)$(1) || wget -O $$@.tmp $(2)$(1) || rm -f $$@.tmp; [ -f $$@.tmp ] || exit 1; if echo "$(3) $$@.tmp" | sha256sum -c -; then mv $$@.tmp $$@; else rm -f $$@.tmp; exit 71; fi' endef -$(eval $(call tar_download,MUSL,musl,1.1.24,.tar.gz,https://www.musl-libc.org/releases/,1370c9a812b2cf2a7d92802510cca0058cc37e66a7bedd70051f0a34015022a3)) +$(eval $(call tar_download,MUSL,musl,1.2.0,.tar.gz,https://musl.libc.org/releases/,c6de7b191139142d3f9a7b5b702c9cae1b5ee6e7f57e582da9328629408fd4e8)) $(eval $(call tar_download,IPERF,iperf,3.7,.tar.gz,https://downloads.es.net/pub/iperf/,d846040224317caf2f75c843d309a950a7db23f9b44b94688ccbe557d6d1710c)) $(eval $(call tar_download,BASH,bash,5.0,.tar.gz,https://ftp.gnu.org/gnu/bash/,b4a80f2ac66170b2913efbfb9f2594f1f76c7b1afd11f799e22035d63077fb4d)) $(eval $(call tar_download,IPROUTE2,iproute2,5.4.0,.tar.xz,https://www.kernel.org/pub/linux/utils/net/iproute2/,fe97aa60a0d4c5ac830be18937e18dc3400ca713a33a89ad896ff1e3d46086ae)) diff --git a/tools/testing/selftests/wireguard/qemu/kernel.config b/tools/testing/selftests/wireguard/qemu/kernel.config index af9323a0b6e0..d531de13c95b 100644 --- a/tools/testing/selftests/wireguard/qemu/kernel.config +++ b/tools/testing/selftests/wireguard/qemu/kernel.config @@ -56,7 +56,6 @@ CONFIG_NO_HZ_IDLE=y CONFIG_NO_HZ_FULL=n CONFIG_HZ_PERIODIC=n CONFIG_HIGH_RES_TIMERS=y -CONFIG_COMPAT_32BIT_TIME=y CONFIG_ARCH_RANDOM=y CONFIG_FILE_LOCKING=y CONFIG_POSIX_TIMERS=y From a5588604af448664e796daf3c1d5a4523c60667b Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 18 Mar 2020 18:30:45 -0600 Subject: [PATCH 3/5] wireguard: queueing: account for skb->protocol==0 We carry out checks to the effect of: if (skb->protocol != wg_examine_packet_protocol(skb)) goto err; By having wg_skb_examine_untrusted_ip_hdr return 0 on failure, this means that the check above still passes in the case where skb->protocol is zero, which is possible to hit with AF_PACKET: struct sockaddr_pkt saddr = { .spkt_device = "wg0" }; unsigned char buffer[5] = { 0 }; sendto(socket(AF_PACKET, SOCK_PACKET, /* skb->protocol = */ 0), buffer, sizeof(buffer), 0, (const struct sockaddr *)&saddr, sizeof(saddr)); Additional checks mean that this isn't actually a problem in the code base, but I could imagine it becoming a problem later if the function is used more liberally. I would prefer to fix this by having wg_examine_packet_protocol return a 32-bit ~0 value on failure, which will never match any value of skb->protocol, which would simply change the generated code from a mov to a movzx. However, sparse complains, and adding __force casts doesn't seem like a good idea, so instead we just add a simple helper function to check for the zero return value. Since wg_examine_packet_protocol itself gets inlined, this winds up not adding an additional branch to the generated code, since the 0 return value already happens in a mergable branch. Reported-by: Fabian Freyer Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- drivers/net/wireguard/device.c | 2 +- drivers/net/wireguard/queueing.h | 8 +++++++- drivers/net/wireguard/receive.c | 4 ++-- 3 files changed, 10 insertions(+), 4 deletions(-) diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c index cdc96968b0f4..3ac3f8570ca1 100644 --- a/drivers/net/wireguard/device.c +++ b/drivers/net/wireguard/device.c @@ -122,7 +122,7 @@ static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev) u32 mtu; int ret; - if (unlikely(wg_skb_examine_untrusted_ip_hdr(skb) != skb->protocol)) { + if (unlikely(!wg_check_packet_protocol(skb))) { ret = -EPROTONOSUPPORT; net_dbg_ratelimited("%s: Invalid IP packet\n", dev->name); goto err; diff --git a/drivers/net/wireguard/queueing.h b/drivers/net/wireguard/queueing.h index fecb559cbdb6..cf1e0e2376d8 100644 --- a/drivers/net/wireguard/queueing.h +++ b/drivers/net/wireguard/queueing.h @@ -66,7 +66,7 @@ struct packet_cb { #define PACKET_PEER(skb) (PACKET_CB(skb)->keypair->entry.peer) /* Returns either the correct skb->protocol value, or 0 if invalid. */ -static inline __be16 wg_skb_examine_untrusted_ip_hdr(struct sk_buff *skb) +static inline __be16 wg_examine_packet_protocol(struct sk_buff *skb) { if (skb_network_header(skb) >= skb->head && (skb_network_header(skb) + sizeof(struct iphdr)) <= @@ -81,6 +81,12 @@ static inline __be16 wg_skb_examine_untrusted_ip_hdr(struct sk_buff *skb) return 0; } +static inline bool wg_check_packet_protocol(struct sk_buff *skb) +{ + __be16 real_protocol = wg_examine_packet_protocol(skb); + return real_protocol && skb->protocol == real_protocol; +} + static inline void wg_reset_packet(struct sk_buff *skb) { skb_scrub_packet(skb, true); diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index 4a153894cee2..243ed7172dd2 100644 --- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -56,7 +56,7 @@ static int prepare_skb_header(struct sk_buff *skb, struct wg_device *wg) size_t data_offset, data_len, header_len; struct udphdr *udp; - if (unlikely(wg_skb_examine_untrusted_ip_hdr(skb) != skb->protocol || + if (unlikely(!wg_check_packet_protocol(skb) || skb_transport_header(skb) < skb->head || (skb_transport_header(skb) + sizeof(struct udphdr)) > skb_tail_pointer(skb))) @@ -388,7 +388,7 @@ static void wg_packet_consume_data_done(struct wg_peer *peer, */ skb->ip_summed = CHECKSUM_UNNECESSARY; skb->csum_level = ~0; /* All levels */ - skb->protocol = wg_skb_examine_untrusted_ip_hdr(skb); + skb->protocol = wg_examine_packet_protocol(skb); if (skb->protocol == htons(ETH_P_IP)) { len = ntohs(ip_hdr(skb)->tot_len); if (unlikely(len < sizeof(struct iphdr))) From 2b8765c52db24c0fbcc81bac9b5e8390f2c7d3c8 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 18 Mar 2020 18:30:46 -0600 Subject: [PATCH 4/5] wireguard: receive: remove dead code from default packet type case The situation in which we wind up hitting the default case here indicates a major bug in earlier parsing code. It is not a usual thing that should ever happen, which means a "friendly" message for it doesn't make sense. Rather, replace this with a WARN_ON, just like we do earlier in the file for a similar situation, so that somebody sends us a bug report and we can fix it. Reported-by: Fabian Freyer Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- drivers/net/wireguard/receive.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index 243ed7172dd2..da3b782ab7d3 100644 --- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -587,8 +587,7 @@ void wg_packet_receive(struct wg_device *wg, struct sk_buff *skb) wg_packet_consume_data(wg, skb); break; default: - net_dbg_skb_ratelimited("%s: Invalid packet from %pISpfsc\n", - wg->dev->name, skb); + WARN(1, "Non-exhaustive parsing of packet header lead to unknown packet type!\n"); goto err; } return; From 11a7686aa99c7fe4b3f80f6dcccd54129817984d Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Wed, 18 Mar 2020 18:30:47 -0600 Subject: [PATCH 5/5] wireguard: noise: error out precomputed DH during handshake rather than config We precompute the static-static ECDH during configuration time, in order to save an expensive computation later when receiving network packets. However, not all ECDH computations yield a contributory result. Prior, we were just not letting those peers be added to the interface. However, this creates a strange inconsistency, since it was still possible to add other weird points, like a valid public key plus a low-order point, and, like points that result in zeros, a handshake would not complete. In order to make the behavior more uniform and less surprising, simply allow all peers to be added. Then, we'll error out later when doing the crypto if there's an issue. This also adds more separation between the crypto layer and the configuration layer. Discussed-with: Mathias Hall-Andersen Signed-off-by: Jason A. Donenfeld Signed-off-by: David S. Miller --- drivers/net/wireguard/netlink.c | 8 +--- drivers/net/wireguard/noise.c | 55 ++++++++++++---------- drivers/net/wireguard/noise.h | 12 ++--- drivers/net/wireguard/peer.c | 7 +-- tools/testing/selftests/wireguard/netns.sh | 15 ++++-- 5 files changed, 49 insertions(+), 48 deletions(-) diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c index bda26405497c..802099c8828a 100644 --- a/drivers/net/wireguard/netlink.c +++ b/drivers/net/wireguard/netlink.c @@ -411,11 +411,7 @@ static int set_peer(struct wg_device *wg, struct nlattr **attrs) peer = wg_peer_create(wg, public_key, preshared_key); if (IS_ERR(peer)) { - /* Similar to the above, if the key is invalid, we skip - * it without fanfare, so that services don't need to - * worry about doing key validation themselves. - */ - ret = PTR_ERR(peer) == -EKEYREJECTED ? 0 : PTR_ERR(peer); + ret = PTR_ERR(peer); peer = NULL; goto out; } @@ -569,7 +565,7 @@ static int wg_set_device(struct sk_buff *skb, struct genl_info *info) private_key); list_for_each_entry_safe(peer, temp, &wg->peer_list, peer_list) { - BUG_ON(!wg_noise_precompute_static_static(peer)); + wg_noise_precompute_static_static(peer); wg_noise_expire_current_peer_keypairs(peer); } wg_cookie_checker_precompute_device_keys(&wg->cookie_checker); diff --git a/drivers/net/wireguard/noise.c b/drivers/net/wireguard/noise.c index 919d9d866446..708dc61c974f 100644 --- a/drivers/net/wireguard/noise.c +++ b/drivers/net/wireguard/noise.c @@ -44,32 +44,23 @@ void __init wg_noise_init(void) } /* Must hold peer->handshake.static_identity->lock */ -bool wg_noise_precompute_static_static(struct wg_peer *peer) +void wg_noise_precompute_static_static(struct wg_peer *peer) { - bool ret; - down_write(&peer->handshake.lock); - if (peer->handshake.static_identity->has_identity) { - ret = curve25519( - peer->handshake.precomputed_static_static, + if (!peer->handshake.static_identity->has_identity || + !curve25519(peer->handshake.precomputed_static_static, peer->handshake.static_identity->static_private, - peer->handshake.remote_static); - } else { - u8 empty[NOISE_PUBLIC_KEY_LEN] = { 0 }; - - ret = curve25519(empty, empty, peer->handshake.remote_static); + peer->handshake.remote_static)) memset(peer->handshake.precomputed_static_static, 0, NOISE_PUBLIC_KEY_LEN); - } up_write(&peer->handshake.lock); - return ret; } -bool wg_noise_handshake_init(struct noise_handshake *handshake, - struct noise_static_identity *static_identity, - const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN], - const u8 peer_preshared_key[NOISE_SYMMETRIC_KEY_LEN], - struct wg_peer *peer) +void wg_noise_handshake_init(struct noise_handshake *handshake, + struct noise_static_identity *static_identity, + const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN], + const u8 peer_preshared_key[NOISE_SYMMETRIC_KEY_LEN], + struct wg_peer *peer) { memset(handshake, 0, sizeof(*handshake)); init_rwsem(&handshake->lock); @@ -81,7 +72,7 @@ bool wg_noise_handshake_init(struct noise_handshake *handshake, NOISE_SYMMETRIC_KEY_LEN); handshake->static_identity = static_identity; handshake->state = HANDSHAKE_ZEROED; - return wg_noise_precompute_static_static(peer); + wg_noise_precompute_static_static(peer); } static void handshake_zero(struct noise_handshake *handshake) @@ -403,6 +394,19 @@ static bool __must_check mix_dh(u8 chaining_key[NOISE_HASH_LEN], return true; } +static bool __must_check mix_precomputed_dh(u8 chaining_key[NOISE_HASH_LEN], + u8 key[NOISE_SYMMETRIC_KEY_LEN], + const u8 precomputed[NOISE_PUBLIC_KEY_LEN]) +{ + static u8 zero_point[NOISE_PUBLIC_KEY_LEN]; + if (unlikely(!crypto_memneq(precomputed, zero_point, NOISE_PUBLIC_KEY_LEN))) + return false; + kdf(chaining_key, key, NULL, precomputed, NOISE_HASH_LEN, + NOISE_SYMMETRIC_KEY_LEN, 0, NOISE_PUBLIC_KEY_LEN, + chaining_key); + return true; +} + static void mix_hash(u8 hash[NOISE_HASH_LEN], const u8 *src, size_t src_len) { struct blake2s_state blake; @@ -531,10 +535,9 @@ wg_noise_handshake_create_initiation(struct message_handshake_initiation *dst, NOISE_PUBLIC_KEY_LEN, key, handshake->hash); /* ss */ - kdf(handshake->chaining_key, key, NULL, - handshake->precomputed_static_static, NOISE_HASH_LEN, - NOISE_SYMMETRIC_KEY_LEN, 0, NOISE_PUBLIC_KEY_LEN, - handshake->chaining_key); + if (!mix_precomputed_dh(handshake->chaining_key, key, + handshake->precomputed_static_static)) + goto out; /* {t} */ tai64n_now(timestamp); @@ -595,9 +598,9 @@ wg_noise_handshake_consume_initiation(struct message_handshake_initiation *src, handshake = &peer->handshake; /* ss */ - kdf(chaining_key, key, NULL, handshake->precomputed_static_static, - NOISE_HASH_LEN, NOISE_SYMMETRIC_KEY_LEN, 0, NOISE_PUBLIC_KEY_LEN, - chaining_key); + if (!mix_precomputed_dh(chaining_key, key, + handshake->precomputed_static_static)) + goto out; /* {t} */ if (!message_decrypt(t, src->encrypted_timestamp, diff --git a/drivers/net/wireguard/noise.h b/drivers/net/wireguard/noise.h index 138a07bb817c..f532d59d3f19 100644 --- a/drivers/net/wireguard/noise.h +++ b/drivers/net/wireguard/noise.h @@ -94,11 +94,11 @@ struct noise_handshake { struct wg_device; void wg_noise_init(void); -bool wg_noise_handshake_init(struct noise_handshake *handshake, - struct noise_static_identity *static_identity, - const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN], - const u8 peer_preshared_key[NOISE_SYMMETRIC_KEY_LEN], - struct wg_peer *peer); +void wg_noise_handshake_init(struct noise_handshake *handshake, + struct noise_static_identity *static_identity, + const u8 peer_public_key[NOISE_PUBLIC_KEY_LEN], + const u8 peer_preshared_key[NOISE_SYMMETRIC_KEY_LEN], + struct wg_peer *peer); void wg_noise_handshake_clear(struct noise_handshake *handshake); static inline void wg_noise_reset_last_sent_handshake(atomic64_t *handshake_ns) { @@ -116,7 +116,7 @@ void wg_noise_expire_current_peer_keypairs(struct wg_peer *peer); void wg_noise_set_static_identity_private_key( struct noise_static_identity *static_identity, const u8 private_key[NOISE_PUBLIC_KEY_LEN]); -bool wg_noise_precompute_static_static(struct wg_peer *peer); +void wg_noise_precompute_static_static(struct wg_peer *peer); bool wg_noise_handshake_create_initiation(struct message_handshake_initiation *dst, diff --git a/drivers/net/wireguard/peer.c b/drivers/net/wireguard/peer.c index 071eedf33f5a..1d634bd3038f 100644 --- a/drivers/net/wireguard/peer.c +++ b/drivers/net/wireguard/peer.c @@ -34,11 +34,8 @@ struct wg_peer *wg_peer_create(struct wg_device *wg, return ERR_PTR(ret); peer->device = wg; - if (!wg_noise_handshake_init(&peer->handshake, &wg->static_identity, - public_key, preshared_key, peer)) { - ret = -EKEYREJECTED; - goto err_1; - } + wg_noise_handshake_init(&peer->handshake, &wg->static_identity, + public_key, preshared_key, peer); if (dst_cache_init(&peer->endpoint_cache, GFP_KERNEL)) goto err_1; if (wg_packet_queue_init(&peer->tx_queue, wg_packet_tx_worker, false, diff --git a/tools/testing/selftests/wireguard/netns.sh b/tools/testing/selftests/wireguard/netns.sh index 138d46b3f330..936e1ca9410e 100755 --- a/tools/testing/selftests/wireguard/netns.sh +++ b/tools/testing/selftests/wireguard/netns.sh @@ -527,11 +527,16 @@ n0 wg set wg0 peer "$pub2" allowed-ips 0.0.0.0/0 n0 wg set wg0 peer "$pub2" allowed-ips ::/0,1700::/111,5000::/4,e000::/37,9000::/75 n0 wg set wg0 peer "$pub2" allowed-ips ::/0 n0 wg set wg0 peer "$pub2" remove -low_order_points=( AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= 4Ot6fDtBuK4WVuP68Z/EatoJjeucMrH9hmIFFl9JuAA= X5yVvKNQjCSx0LFVnIPvWwREXMRYHI6G2CJO3dCfEVc= 7P///////////////////////////////////////38= 7f///////////////////////////////////////38= 7v///////////////////////////////////////38= ) -n0 wg set wg0 private-key /dev/null ${low_order_points[@]/#/peer } -[[ -z $(n0 wg show wg0 peers) ]] -n0 wg set wg0 private-key <(echo "$key1") ${low_order_points[@]/#/peer } -[[ -z $(n0 wg show wg0 peers) ]] +for low_order_point in AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= AQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA= 4Ot6fDtBuK4WVuP68Z/EatoJjeucMrH9hmIFFl9JuAA= X5yVvKNQjCSx0LFVnIPvWwREXMRYHI6G2CJO3dCfEVc= 7P///////////////////////////////////////38= 7f///////////////////////////////////////38= 7v///////////////////////////////////////38=; do + n0 wg set wg0 peer "$low_order_point" persistent-keepalive 1 endpoint 127.0.0.1:1111 +done +[[ -n $(n0 wg show wg0 peers) ]] +exec 4< <(n0 ncat -l -u -p 1111) +ncat_pid=$! +waitncatudp $netns0 $ncat_pid +ip0 link set wg0 up +! read -r -n 1 -t 2 <&4 || false +kill $ncat_pid ip0 link del wg0 declare -A objects