Hi Jakub,
Sorry to send these patches during the merge window, but they're net
fixes, not netdev enhancements, and while I'd ordinarily wait anyway,
I just got a first bug report for one of these fixes, which I originally
had thought was mostly unlikely. So please apply the following three
patches to net:
1) Make proper use of nr_cpu_ids with cpumask_next(), rather than
awkwardly using modulo, to handle dynamic CPU topology changes.
Linus noticed this a while ago and pointed it out, and today a user
actually got hit by it.
2) Respect persistent keepalive and other staged packets when setting
the private key after the interface is already up.
3) Use timer_delete_sync() instead of del_timer_sync(), per the
documentation.
Thanks,
Jason
Jason A. Donenfeld (3):
wireguard: queueing: use saner cpu selection wrapping
wireguard: netlink: send staged packets when setting initial private
key
wireguard: timers: move to using timer_delete_sync
drivers/net/wireguard/netlink.c | 14 ++++++----
drivers/net/wireguard/queueing.c | 1 +
drivers/net/wireguard/queueing.h | 25 ++++++++----------
drivers/net/wireguard/receive.c | 2 +-
drivers/net/wireguard/send.c | 2 +-
drivers/net/wireguard/timers.c | 10 ++++----
tools/testing/selftests/wireguard/netns.sh | 30 +++++++++++++++++++---
7 files changed, 54 insertions(+), 30 deletions(-)
--
2.41.0
Packets bound for peers can queue up prior to the device private key
being set. For example, if persistent keepalive is set, a packet is
queued up to be sent as soon as the device comes up. However, if the
private key hasn't been set yet, the handshake message never sends, and
no timer is armed to retry, since that would be pointless.
But, if a user later sets a private key, the expectation is that those
queued packets, such as a persistent keepalive, are actually sent. So
adjust the configuration logic to account for this edge case, and add a
test case to make sure this works.
Maxim noticed this with a wg-quick(8) config to the tune of:
[Interface]
PostUp = wg set %i private-key somefile
[Peer]
PublicKey = ...
Endpoint = ...
PersistentKeepalive = 25
Here, the private key gets set after the device comes up using a PostUp
script, triggering the bug.
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel")
Cc: [email protected]
Reported-by: Maxim Cournoyer <[email protected]>
Tested-by: Maxim Cournoyer <[email protected]>
Link: https://lore.kernel.org/wireguard/[email protected]/
Signed-off-by: Jason A. Donenfeld <[email protected]>
---
drivers/net/wireguard/netlink.c | 14 ++++++----
tools/testing/selftests/wireguard/netns.sh | 30 +++++++++++++++++++---
2 files changed, 35 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireguard/netlink.c b/drivers/net/wireguard/netlink.c
index 43c8c84e7ea8..6d1bd9f52d02 100644
--- a/drivers/net/wireguard/netlink.c
+++ b/drivers/net/wireguard/netlink.c
@@ -546,6 +546,7 @@ static int wg_set_device(struct sk_buff *skb, struct genl_info *info)
u8 *private_key = nla_data(info->attrs[WGDEVICE_A_PRIVATE_KEY]);
u8 public_key[NOISE_PUBLIC_KEY_LEN];
struct wg_peer *peer, *temp;
+ bool send_staged_packets;
if (!crypto_memneq(wg->static_identity.static_private,
private_key, NOISE_PUBLIC_KEY_LEN))
@@ -564,14 +565,17 @@ static int wg_set_device(struct sk_buff *skb, struct genl_info *info)
}
down_write(&wg->static_identity.lock);
- wg_noise_set_static_identity_private_key(&wg->static_identity,
- private_key);
- list_for_each_entry_safe(peer, temp, &wg->peer_list,
- peer_list) {
+ send_staged_packets = !wg->static_identity.has_identity && netif_running(wg->dev);
+ wg_noise_set_static_identity_private_key(&wg->static_identity, private_key);
+ send_staged_packets = send_staged_packets && wg->static_identity.has_identity;
+
+ wg_cookie_checker_precompute_device_keys(&wg->cookie_checker);
+ list_for_each_entry_safe(peer, temp, &wg->peer_list, peer_list) {
wg_noise_precompute_static_static(peer);
wg_noise_expire_current_peer_keypairs(peer);
+ if (send_staged_packets)
+ wg_packet_send_staged_packets(peer);
}
- wg_cookie_checker_precompute_device_keys(&wg->cookie_checker);
up_write(&wg->static_identity.lock);
}
skip_set_private_key:
diff --git a/tools/testing/selftests/wireguard/netns.sh b/tools/testing/selftests/wireguard/netns.sh
index 69c7796c7ca9..405ff262ca93 100755
--- a/tools/testing/selftests/wireguard/netns.sh
+++ b/tools/testing/selftests/wireguard/netns.sh
@@ -514,10 +514,32 @@ n2 bash -c 'printf 0 > /proc/sys/net/ipv4/conf/all/rp_filter'
n1 ping -W 1 -c 1 192.168.241.2
[[ $(n2 wg show wg0 endpoints) == "$pub1 10.0.0.3:1" ]]
-ip1 link del veth1
-ip1 link del veth3
-ip1 link del wg0
-ip2 link del wg0
+ip1 link del dev veth3
+ip1 link del dev wg0
+ip2 link del dev wg0
+
+# Make sure persistent keep alives are sent when an adapter comes up
+ip1 link add dev wg0 type wireguard
+n1 wg set wg0 private-key <(echo "$key1") peer "$pub2" endpoint 10.0.0.1:1 persistent-keepalive 1
+read _ _ tx_bytes < <(n1 wg show wg0 transfer)
+[[ $tx_bytes -eq 0 ]]
+ip1 link set dev wg0 up
+read _ _ tx_bytes < <(n1 wg show wg0 transfer)
+[[ $tx_bytes -gt 0 ]]
+ip1 link del dev wg0
+# This should also happen even if the private key is set later
+ip1 link add dev wg0 type wireguard
+n1 wg set wg0 peer "$pub2" endpoint 10.0.0.1:1 persistent-keepalive 1
+read _ _ tx_bytes < <(n1 wg show wg0 transfer)
+[[ $tx_bytes -eq 0 ]]
+ip1 link set dev wg0 up
+read _ _ tx_bytes < <(n1 wg show wg0 transfer)
+[[ $tx_bytes -eq 0 ]]
+n1 wg set wg0 private-key <(echo "$key1")
+read _ _ tx_bytes < <(n1 wg show wg0 transfer)
+[[ $tx_bytes -gt 0 ]]
+ip1 link del dev veth1
+ip1 link del dev wg0
# We test that Netlink/IPC is working properly by doing things that usually cause split responses
ip0 link add dev wg0 type wireguard
--
2.41.0