==================================================================
BUG: KCSAN: data-race in complete_signal / do_signal_stop

write to 0xffff88812f3db02c of 4 bytes by task 10056 on cpu 0:
 freezer_count include/linux/freezer.h:121 [inline]
 freezable_schedule include/linux/freezer.h:173 [inline]
 do_signal_stop+0x562/0x6d0 kernel/signal.c:2400
 get_signal+0x788/0x14e0 kernel/signal.c:2635
 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x11a/0x1b0 kernel/entry/common.c:208
 irqentry_exit_to_user_mode+0x5/0x20 kernel/entry/common.c:314
 irqentry_exit+0xe/0x40 kernel/entry/common.c:405
 asm_sysvec_reschedule_ipi+0x12/0x20 arch/x86/include/asm/idtentry.h:637

read to 0xffff88812f3db02c of 4 bytes by interrupt on cpu 1:
 wants_signal kernel/signal.c:982 [inline]
 complete_signal+0x7c/0x600 kernel/signal.c:1005
 send_sigqueue+0x268/0x430 kernel/signal.c:1885
 posix_timer_event kernel/time/posix-timers.c:354 [inline]
 posix_timer_fn+0xe8/0x210 kernel/time/posix-timers.c:380
 __run_hrtimer+0x163/0x460 kernel/time/hrtimer.c:1537
 __hrtimer_run_queues kernel/time/hrtimer.c:1601 [inline]
 hrtimer_interrupt+0x380/0xaf0 kernel/time/hrtimer.c:1663
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1089 [inline]
 __sysvec_apic_timer_interrupt+0x6f/0x200 arch/x86/kernel/apic/apic.c:1106
 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:632
 __preempt_count_dec_and_test arch/x86/include/asm/preempt.h:95 [inline]
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
 _raw_spin_unlock_irq+0x2c/0x40 kernel/locking/spinlock.c:199
 finish_lock_switch kernel/sched/core.c:4074 [inline]
 finish_task_switch+0xc0/0x2a0 kernel/sched/core.c:4191
 context_switch kernel/sched/core.c:4325 [inline]
 __schedule+0x3c1/0x580 kernel/sched/core.c:5073
 schedule+0x7f/0xb0 kernel/sched/core.c:5152
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_signal_stop+0x548/0x6d0 kernel/signal.c:2400
 get_signal+0x65d/0x14e0 kernel/signal.c:2737
 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:789
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x11a/0x1b0 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 10060 Comm: syz-executor.0 Not tainted 5.12.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================