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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:1465
 __run_timers+0x358/0x420 kernel/time/timer.c:1732
 run_timer_softirq+0x19/0x30 kernel/time/timer.c:1745
 __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
 is_atomic kernel/kcsan/core.c:238 [inline]
 should_watch kernel/kcsan/core.c:266 [inline]
 check_access kernel/kcsan/core.c:642 [inline]
 __tsan_read1+0x11a/0x180 kernel/kcsan/core.c:861
 xfrm_state_find+0x501/0x29b0 net/xfrm/xfrm_state.c:1098
 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2399 [inline]
 xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2444 [inline]
 xfrm_resolve_and_create_bundle+0x499/0x1a40 net/xfrm/xfrm_policy.c:2734
 xfrm_lookup_with_ifid+0xbbf/0x15b0 net/xfrm/xfrm_policy.c:3068
 xfrm_lookup net/xfrm/xfrm_policy.c:3192 [inline]
 xfrm_lookup_route+0x37/0xf0 net/xfrm/xfrm_policy.c:3203
 ip6_dst_lookup_flow+0x94/0xc0 net/ipv6/ip6_output.c:1228
 rawv6_sendmsg+0xb8a/0x1380 net/ipv6/raw.c:928
 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 29096 on cpu 0:
 try_to_del_timer_sync+0xe3/0x290 kernel/time/timer.c:1233
 del_timer_sync kernel/time/timer.c:1380 [inline]
 schedule_timeout+0x108/0x240 kernel/time/timer.c:1880
 schedule_timeout_uninterruptible+0x2c/0x30 kernel/time/timer.c:1913
 snd_use_lock_sync_helper+0x7d/0xf0 sound/core/seq/seq_lock.c:23
 snd_seq_fifo_clear+0x39/0x160 sound/core/seq/seq_fifo.c:90
 snd_seq_ioctl_remove_events+0x79/0xd0 sound/core/seq/seq_clientmgr.c:1920
 snd_seq_ioctl+0x156/0x250 sound/core/seq/seq_clientmgr.c:2173
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl+0xcb/0x140 fs/ioctl.c:1055
 __x64_sys_ioctl+0x3f/0x50 fs/ioctl.c:1055
 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

value changed: 0xffffc900058b7cc8 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 29096 Comm: syz-executor.1 Tainted: G        W         5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
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