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| author | Eric Dumazet <edumazet@google.com> | 2019-10-30 23:00:04 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-10-30 23:24:25 +0300 |
| commit | 7170a977743b72cf3eb46ef6ef89885dc7ad3621 (patch) | |
| tree | 2f399aeb5a308d3df34fa88d2029c1a4949bf8eb /net/ipv4/udp.c | |
| parent | b7265a0df82c1716bf788096217083ed65a8bb14 (diff) | |
| download | linux-7170a977743b72cf3eb46ef6ef89885dc7ad3621.tar.xz | |
net: annotate accesses to sk->sk_incoming_cpu
This socket field can be read and written by concurrent cpus.
Use READ_ONCE() and WRITE_ONCE() annotations to document this,
and avoid some compiler 'optimizations'.
KCSAN reported :
BUG: KCSAN: data-race in tcp_v4_rcv / tcp_v4_rcv
write to 0xffff88812220763c of 4 bytes by interrupt on cpu 0:
sk_incoming_cpu_update include/net/sock.h:953 [inline]
tcp_v4_rcv+0x1b3c/0x1bb0 net/ipv4/tcp_ipv4.c:1934
ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
__netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
process_backlog+0x1d3/0x420 net/core/dev.c:5955
napi_poll net/core/dev.c:6392 [inline]
net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
__do_softirq+0x115/0x33f kernel/softirq.c:292
do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1082
do_softirq.part.0+0x6b/0x80 kernel/softirq.c:337
do_softirq kernel/softirq.c:329 [inline]
__local_bh_enable_ip+0x76/0x80 kernel/softirq.c:189
read to 0xffff88812220763c of 4 bytes by interrupt on cpu 1:
sk_incoming_cpu_update include/net/sock.h:952 [inline]
tcp_v4_rcv+0x181a/0x1bb0 net/ipv4/tcp_ipv4.c:1934
ip_protocol_deliver_rcu+0x4d/0x420 net/ipv4/ip_input.c:204
ip_local_deliver_finish+0x110/0x140 net/ipv4/ip_input.c:231
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_local_deliver+0x133/0x210 net/ipv4/ip_input.c:252
dst_input include/net/dst.h:442 [inline]
ip_rcv_finish+0x121/0x160 net/ipv4/ip_input.c:413
NF_HOOK include/linux/netfilter.h:305 [inline]
NF_HOOK include/linux/netfilter.h:299 [inline]
ip_rcv+0x18f/0x1a0 net/ipv4/ip_input.c:523
__netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010
__netif_receive_skb+0x37/0xf0 net/core/dev.c:5124
process_backlog+0x1d3/0x420 net/core/dev.c:5955
napi_poll net/core/dev.c:6392 [inline]
net_rx_action+0x3ae/0xa90 net/core/dev.c:6460
__do_softirq+0x115/0x33f kernel/softirq.c:292
run_ksoftirqd+0x46/0x60 kernel/softirq.c:603
smpboot_thread_fn+0x37d/0x4a0 kernel/smpboot.c:165
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index d1ed160af202..1d58ce829dca 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -388,7 +388,7 @@ static int compute_score(struct sock *sk, struct net *net, return -1; score += 4; - if (sk->sk_incoming_cpu == raw_smp_processor_id()) + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) score++; return score; } |