| From foo@baz Wed 06 Nov 2019 04:08:37 PM CET |
| From: Eric Dumazet <edumazet@google.com> |
| Date: Wed, 30 Oct 2019 13:00:04 -0700 |
| Subject: net: annotate accesses to sk->sk_incoming_cpu |
| |
| From: Eric Dumazet <edumazet@google.com> |
| |
| [ Upstream commit 7170a977743b72cf3eb46ef6ef89885dc7ad3621 ] |
| |
| 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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| include/net/sock.h | 4 ++-- |
| net/core/sock.c | 4 ++-- |
| net/ipv4/inet_hashtables.c | 2 +- |
| net/ipv4/udp.c | 2 +- |
| net/ipv6/inet6_hashtables.c | 2 +- |
| net/ipv6/udp.c | 2 +- |
| 6 files changed, 8 insertions(+), 8 deletions(-) |
| |
| --- a/include/net/sock.h |
| +++ b/include/net/sock.h |
| @@ -916,8 +916,8 @@ static inline void sk_incoming_cpu_updat |
| { |
| int cpu = raw_smp_processor_id(); |
| |
| - if (unlikely(sk->sk_incoming_cpu != cpu)) |
| - sk->sk_incoming_cpu = cpu; |
| + if (unlikely(READ_ONCE(sk->sk_incoming_cpu) != cpu)) |
| + WRITE_ONCE(sk->sk_incoming_cpu, cpu); |
| } |
| |
| static inline void sock_rps_record_flow_hash(__u32 hash) |
| --- a/net/core/sock.c |
| +++ b/net/core/sock.c |
| @@ -1039,7 +1039,7 @@ set_rcvbuf: |
| break; |
| |
| case SO_INCOMING_CPU: |
| - sk->sk_incoming_cpu = val; |
| + WRITE_ONCE(sk->sk_incoming_cpu, val); |
| break; |
| |
| case SO_CNX_ADVICE: |
| @@ -1351,7 +1351,7 @@ int sock_getsockopt(struct socket *sock, |
| break; |
| |
| case SO_INCOMING_CPU: |
| - v.val = sk->sk_incoming_cpu; |
| + v.val = READ_ONCE(sk->sk_incoming_cpu); |
| break; |
| |
| case SO_MEMINFO: |
| --- a/net/ipv4/inet_hashtables.c |
| +++ b/net/ipv4/inet_hashtables.c |
| @@ -193,7 +193,7 @@ static inline int compute_score(struct s |
| if (sk->sk_bound_dev_if) |
| 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; |
| --- a/net/ipv4/udp.c |
| +++ b/net/ipv4/udp.c |
| @@ -419,7 +419,7 @@ static int compute_score(struct sock *sk |
| 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; |
| } |
| --- a/net/ipv6/inet6_hashtables.c |
| +++ b/net/ipv6/inet6_hashtables.c |
| @@ -118,7 +118,7 @@ static inline int compute_score(struct s |
| if (sk->sk_bound_dev_if) |
| score++; |
| } |
| - if (sk->sk_incoming_cpu == raw_smp_processor_id()) |
| + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) |
| score++; |
| } |
| return score; |
| --- a/net/ipv6/udp.c |
| +++ b/net/ipv6/udp.c |
| @@ -170,7 +170,7 @@ static int compute_score(struct sock *sk |
| score++; |
| } |
| |
| - if (sk->sk_incoming_cpu == raw_smp_processor_id()) |
| + if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id()) |
| score++; |
| |
| return score; |