From 93da8d75a66568ba4bb5b14ad2833acd7304cd02 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 17 Nov 2023 14:17:33 +0000 Subject: wireguard: use DEV_STATS_INC() 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 Signed-off-by: Eric Dumazet Cc: Jason A. Donenfeld Cc: Hangbin Liu Signed-off-by: Jason A. Donenfeld Reviewed-by: Hangbin Liu Signed-off-by: David S. Miller --- drivers/net/wireguard/device.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/net/wireguard/device.c') diff --git a/drivers/net/wireguard/device.c b/drivers/net/wireguard/device.c index 258dcc103921..deb9636b0ecf 100644 --- a/drivers/net/wireguard/device.c +++ b/drivers/net/wireguard/device.c @@ -210,7 +210,7 @@ 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); @@ -228,7 +228,7 @@ err_icmp: 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; } -- cgit