BUG: using __this_cpu_add() in preemptible [00000000] code: syz-executor.4/3559
caller is __this_cpu_preempt_check+0x1d/0x30 lib/smp_processor_id.c:62
CPU: 1 PID: 3559 Comm: syz-executor.4 Not tainted 4.4.174+ #4
 0000000000000000 cb7079631375a33e ffff8801cf11f678 ffffffff81aad1a1
 ffff8801d42797c0 0000000000000001 ffffffff82a861e0 ffffffff8292c040
 0000000000000001 ffff8801cf11f6b8 ffffffff81b0ad83 ffff8801d42bf400
Call Trace:
 [<ffffffff81aad1a1>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aad1a1>] dump_stack+0xc1/0x120 lib/dump_stack.c:51
 [<ffffffff81b0ad83>] check_preemption_disabled+0x1d3/0x200 lib/smp_processor_id.c:46
 [<ffffffff81b0aded>] __this_cpu_preempt_check+0x1d/0x30 lib/smp_processor_id.c:62
 [<ffffffff8240fcf5>] tcp_try_coalesce net/ipv4/tcp_input.c:4293 [inline]
 [<ffffffff8240fcf5>] tcp_try_coalesce+0x245/0x510 net/ipv4/tcp_input.c:4275
 [<ffffffff824100e7>] tcp_queue_rcv+0x127/0x6f0 net/ipv4/tcp_input.c:4539
 [<ffffffff8242494e>] tcp_send_rcvq+0x3de/0x4a0 net/ipv4/tcp_input.c:4585
 [<ffffffff823fd062>] tcp_sendmsg+0x2332/0x2ab0 net/ipv4/tcp.c:1134
 [<ffffffff824a8b42>] inet_sendmsg+0x202/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821d838e>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821d838e>] sock_sendmsg+0xbe/0x110 net/socket.c:648
 [<ffffffff821d9e69>] ___sys_sendmsg+0x369/0x890 net/socket.c:1975
 [<ffffffff821dd2e0>] __sys_sendmmsg+0x130/0x2e0 net/socket.c:2060
 [<ffffffff821dd4c5>] SYSC_sendmmsg net/socket.c:2090 [inline]
 [<ffffffff821dd4c5>] SyS_sendmmsg+0x35/0x60 net/socket.c:2085
 [<ffffffff82718ba1>] entry_SYSCALL_64_fastpath+0x1e/0x9a
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Dropping request.  Check SNMP counters.
TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Dropping request.  Check SNMP counters.