6.1-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit 93da8d75a66568ba4bb5b14ad2833acd7304cd02 ]
wg_xmit() can be called concurrently, KCSAN reported [1] some device stats updates can be lost.
Use DEV_STATS_INC() for this unlikely case.
[1] BUG: KCSAN: data-race in wg_xmit / wg_xmit
read-write to 0xffff888104239160 of 8 bytes by task 1375 on cpu 0: wg_xmit+0x60f/0x680 drivers/net/wireguard/device.c:231 __netdev_start_xmit include/linux/netdevice.h:4918 [inline] netdev_start_xmit include/linux/netdevice.h:4932 [inline] xmit_one net/core/dev.c:3543 [inline] dev_hard_start_xmit+0x11b/0x3f0 net/core/dev.c:3559 ...
read-write to 0xffff888104239160 of 8 bytes by task 1378 on cpu 1: wg_xmit+0x60f/0x680 drivers/net/wireguard/device.c:231 __netdev_start_xmit include/linux/netdevice.h:4918 [inline] netdev_start_xmit include/linux/netdevice.h:4932 [inline] xmit_one net/core/dev.c:3543 [inline] dev_hard_start_xmit+0x11b/0x3f0 net/core/dev.c:3559 ...
v2: also change wg_packet_consume_data_done() (Hangbin Liu) and wg_packet_purge_staged_packets()
Fixes: e7096c131e51 ("net: WireGuard secure network tunnel") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Eric Dumazet edumazet@google.com Cc: Jason A. Donenfeld Jason@zx2c4.com Cc: Hangbin Liu liuhangbin@gmail.com Signed-off-by: Jason A. Donenfeld Jason@zx2c4.com Reviewed-by: Hangbin Liu liuhangbin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/wireguard/device.c | 4 ++-- drivers/net/wireguard/receive.c | 12 ++++++------ drivers/net/wireguard/send.c | 3 ++- 3 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c index d58e9f818d3b7..895a621c9e267 100644 --- a/drivers/net/wireguard/device.c +++ b/drivers/net/wireguard/device.c @@ -209,7 +209,7 @@ static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev) */ while (skb_queue_len(&peer->staged_packet_queue) > MAX_STAGED_PACKETS) { dev_kfree_skb(__skb_dequeue(&peer->staged_packet_queue)); - ++dev->stats.tx_dropped; + DEV_STATS_INC(dev, tx_dropped); } skb_queue_splice_tail(&packets, &peer->staged_packet_queue); spin_unlock_bh(&peer->staged_packet_queue.lock); @@ -227,7 +227,7 @@ static netdev_tx_t wg_xmit(struct sk_buff *skb, struct net_device *dev) else if (skb->protocol == htons(ETH_P_IPV6)) icmpv6_ndo_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0); err: - ++dev->stats.tx_errors; + DEV_STATS_INC(dev, tx_errors); kfree_skb(skb); return ret; } diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index 0b3f0c8435509..a176653c88616 100644 --- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -416,20 +416,20 @@ static void wg_packet_consume_data_done(struct wg_peer *peer, net_dbg_skb_ratelimited("%s: Packet has unallowed src IP (%pISc) from peer %llu (%pISpfsc)\n", dev->name, skb, peer->internal_id, &peer->endpoint.addr); - ++dev->stats.rx_errors; - ++dev->stats.rx_frame_errors; + DEV_STATS_INC(dev, rx_errors); + DEV_STATS_INC(dev, rx_frame_errors); goto packet_processed; dishonest_packet_type: net_dbg_ratelimited("%s: Packet is neither ipv4 nor ipv6 from peer %llu (%pISpfsc)\n", dev->name, peer->internal_id, &peer->endpoint.addr); - ++dev->stats.rx_errors; - ++dev->stats.rx_frame_errors; + DEV_STATS_INC(dev, rx_errors); + DEV_STATS_INC(dev, rx_frame_errors); goto packet_processed; dishonest_packet_size: net_dbg_ratelimited("%s: Packet has incorrect size from peer %llu (%pISpfsc)\n", dev->name, peer->internal_id, &peer->endpoint.addr); - ++dev->stats.rx_errors; - ++dev->stats.rx_length_errors; + DEV_STATS_INC(dev, rx_errors); + DEV_STATS_INC(dev, rx_length_errors); goto packet_processed; packet_processed: dev_kfree_skb(skb); diff --git a/drivers/net/wireguard/send.c b/drivers/net/wireguard/send.c index 95c853b59e1da..0d48e0f4a1ba3 100644 --- a/drivers/net/wireguard/send.c +++ b/drivers/net/wireguard/send.c @@ -333,7 +333,8 @@ static void wg_packet_create_data(struct wg_peer *peer, struct sk_buff *first) void wg_packet_purge_staged_packets(struct wg_peer *peer) { spin_lock_bh(&peer->staged_packet_queue.lock); - peer->device->dev->stats.tx_dropped += peer->staged_packet_queue.qlen; + DEV_STATS_ADD(peer->device->dev, tx_dropped, + peer->staged_packet_queue.qlen); __skb_queue_purge(&peer->staged_packet_queue); spin_unlock_bh(&peer->staged_packet_queue.lock); }