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BUG: KCSAN: data-race in expire_timers / try_to_del_timer_sync

write to 0xffff888237d376c8 of 8 bytes by interrupt on cpu 1:
 expire_timers+0x13d/0x250 kernel/time/timer.c:1463
 __run_timers+0x358/0x420 kernel/time/timer.c:1731
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1744
 __do_softirq+0x12c/0x26e kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x9a/0xb0 kernel/softirq.c:636
 sysvec_apic_timer_interrupt+0x69/0x80 arch/x86/kernel/apic/apic.c:1100
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
 memcmp+0x4b/0x60 lib/string.c:941
 __flow_hash_consistentify net/core/flow_dissector.c:1527 [inline]
 __flow_hash_from_keys+0xbd/0x3a0 net/core/flow_dissector.c:1548
 flow_hash_from_keys net/core/flow_dissector.c:1561 [inline]
 __get_hash_from_flowi6+0xff/0x170 net/core/flow_dissector.c:1736
 skb_get_hash_flowi6 include/linux/skbuff.h:1390 [inline]
 ip6_make_flowlabel include/net/ipv6.h:883 [inline]
 __ip6_make_skb+0x949/0xe40 net/ipv6/ip6_output.c:1902
 ip6_finish_skb include/net/ipv6.h:1027 [inline]
 ip6_push_pending_frames+0x76/0x170 net/ipv6/ip6_output.c:1950
 rawv6_push_pending_frames net/ipv6/raw.c:613 [inline]
 rawv6_sendmsg+0x12ab/0x1380 net/ipv6/raw.c:956
 inet_sendmsg+0x5f/0x80 net/ipv4/af_inet.c:821
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg net/socket.c:723 [inline]
 ____sys_sendmsg+0x360/0x4d0 net/socket.c:2392
 ___sys_sendmsg net/socket.c:2446 [inline]
 __sys_sendmmsg+0x315/0x4b0 net/socket.c:2532
 __do_sys_sendmmsg net/socket.c:2561 [inline]
 __se_sys_sendmmsg net/socket.c:2558 [inline]
 __x64_sys_sendmmsg+0x53/0x60 net/socket.c:2558
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888237d376c8 of 8 bytes by task 1778 on cpu 0:
 try_to_del_timer_sync+0xe3/0x290 kernel/time/timer.c:1231
 del_timer_sync kernel/time/timer.c:1378 [inline]
 schedule_timeout+0x108/0x240 kernel/time/timer.c:1879
 do_wait_for_common kernel/sched/completion.c:85 [inline]
 __wait_for_common kernel/sched/completion.c:106 [inline]
 wait_for_common+0xc6/0x150 kernel/sched/completion.c:117
 io_ring_exit_work+0x221/0x1350 fs/io_uring.c:8780
 process_one_work+0x3e9/0x8f0 kernel/workqueue.c:2276
 worker_thread+0x636/0xae0 kernel/workqueue.c:2422
 kthread+0x262/0x280 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

value changed: 0xffffc9000043fc50 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 1778 Comm: kworker/u4:3 Tainted: G        W         5.14.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events_unbound io_ring_exit_work
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