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| author | zhudi <zhudi21@huawei.com> | 2020-08-26 20:01:13 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2020-08-28 06:51:11 -0700 |
| commit | 174bce38caf18b47816f352156fab926f4fe072a (patch) | |
| tree | 08890cd5ece932e9090355bbc905aefdfc08361d /net/netlink | |
| parent | 51458c97058deaec49f9d42028450e7a404c0653 (diff) | |
| download | lwn-174bce38caf18b47816f352156fab926f4fe072a.tar.gz lwn-174bce38caf18b47816f352156fab926f4fe072a.zip | |
netlink: fix a data race in netlink_rcv_wake()
The data races were reported by KCSAN:
BUG: KCSAN: data-race in netlink_recvmsg / skb_queue_tail
write (marked) to 0xffff8c0986e5a8c8 of 8 bytes by interrupt on cpu 3:
skb_queue_tail+0xcc/0x120
__netlink_sendskb+0x55/0x80
netlink_broadcast_filtered+0x465/0x7e0
nlmsg_notify+0x8f/0x120
rtnl_notify+0x8e/0xb0
__neigh_notify+0xf2/0x120
neigh_update+0x927/0xde0
arp_process+0x8a3/0xf50
arp_rcv+0x27c/0x3b0
__netif_receive_skb_core+0x181c/0x1840
__netif_receive_skb+0x38/0xf0
netif_receive_skb_internal+0x77/0x1c0
napi_gro_receive+0x1bd/0x1f0
e1000_clean_rx_irq+0x538/0xb20 [e1000]
e1000_clean+0x5e4/0x1340 [e1000]
net_rx_action+0x310/0x9d0
__do_softirq+0xe8/0x308
irq_exit+0x109/0x110
do_IRQ+0x7f/0xe0
ret_from_intr+0x0/0x1d
0xffffffffffffffff
read to 0xffff8c0986e5a8c8 of 8 bytes by task 1463 on cpu 0:
netlink_recvmsg+0x40b/0x820
sock_recvmsg+0xc9/0xd0
___sys_recvmsg+0x1a4/0x3b0
__sys_recvmsg+0x86/0x120
__x64_sys_recvmsg+0x52/0x70
do_syscall_64+0xb5/0x360
entry_SYSCALL_64_after_hwframe+0x65/0xca
0xffffffffffffffff
Since the write is under sk_receive_queue->lock but the read
is done as lockless. so fix it by using skb_queue_empty_lockless()
instead of skb_queue_empty() for the read in netlink_rcv_wake()
Signed-off-by: zhudi <zhudi21@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
| -rw-r--r-- | net/netlink/af_netlink.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index b5f30d7d30d0..d2d1448274f5 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -353,7 +353,7 @@ static void netlink_rcv_wake(struct sock *sk) { struct netlink_sock *nlk = nlk_sk(sk); - if (skb_queue_empty(&sk->sk_receive_queue)) + if (skb_queue_empty_lockless(&sk->sk_receive_queue)) clear_bit(NETLINK_S_CONGESTED, &nlk->state); if (!test_bit(NETLINK_S_CONGESTED, &nlk->state)) wake_up_interruptible(&nlk->wait); |