tcp: fix data-race in tcp_recvmsg()
Reading tp->recvmsg_inq after socket lock is released
raises a KCSAN warning [1]
Replace has_tss & has_cmsg by cmsg_flags and make
sure to not read tp->recvmsg_inq a second time.
[1]
BUG: KCSAN: data-race in tcp_chrono_stop / tcp_recvmsg
write to 0xffff888126adef24 of 2 bytes by interrupt on cpu 0:
tcp_chrono_set net/ipv4/tcp_output.c:2309 [inline]
tcp_chrono_stop+0x14c/0x280 net/ipv4/tcp_output.c:2338
tcp_clean_rtx_queue net/ipv4/tcp_input.c:3165 [inline]
tcp_ack+0x274f/0x3170 net/ipv4/tcp_input.c:3688
tcp_rcv_established+0x37e/0xf50 net/ipv4/tcp_input.c:5696
tcp_v4_do_rcv+0x381/0x4e0 net/ipv4/tcp_ipv4.c:1561
tcp_v4_rcv+0x19dc/0x1bb0 net/ipv4/tcp_ipv4.c:1942
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
netif_receive_skb_internal+0x59/0x190 net/core/dev.c:5214
napi_skb_finish net/core/dev.c:5677 [inline]
napi_gro_receive+0x28f/0x330 net/core/dev.c:5710
read to 0xffff888126adef25 of 1 bytes by task 7275 on cpu 1:
tcp_recvmsg+0x77b/0x1a30 net/ipv4/tcp.c:2187
inet_recvmsg+0xbb/0x250 net/ipv4/af_inet.c:838
sock_recvmsg_nosec net/socket.c:871 [inline]
sock_recvmsg net/socket.c:889 [inline]
sock_recvmsg+0x92/0xb0 net/socket.c:885
sock_read_iter+0x15f/0x1e0 net/socket.c:967
call_read_iter include/linux/fs.h:1889 [inline]
new_sync_read+0x389/0x4f0 fs/read_write.c:414
__vfs_read+0xb1/0xc0 fs/read_write.c:427
vfs_read fs/read_write.c:461 [inline]
vfs_read+0x143/0x2c0 fs/read_write.c:446
ksys_read+0xd5/0x1b0 fs/read_write.c:587
__do_sys_read fs/read_write.c:597 [inline]
__se_sys_read fs/read_write.c:595 [inline]
__x64_sys_read+0x4c/0x60 fs/read_write.c:595
do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7275 Comm: sshd Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: b75eba76d3d7 ("tcp: send in-queue bytes in cmsg upon read")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 file changed