==================================================================
BUG: KCSAN: data-race in futex_wait_queue_me / prepare_signal

read-write to 0xffff888105ea002c of 4 bytes by task 8441 on cpu 1:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 freezable_schedule include/linux/freezer.h:171 [inline]
 futex_wait_queue_me+0x17e/0x240 kernel/futex.c:2602
 futex_wait+0x145/0x3d0 kernel/futex.c:2704
 do_futex+0x105a/0x20c0 kernel/futex.c:3763
 __do_sys_futex kernel/futex.c:3826 [inline]
 __se_sys_futex+0x2a8/0x390 kernel/futex.c:3792
 __x64_sys_futex+0x74/0x80 kernel/futex.c:3792
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888105ea002c of 4 bytes by task 8439 on cpu 0:
 sig_task_ignored kernel/signal.c:94 [inline]
 sig_ignored kernel/signal.c:119 [inline]
 prepare_signal+0x872/0xd80 kernel/signal.c:962
 __send_signal+0x64/0x780 kernel/signal.c:1082
 send_signal+0x39f/0x3d0 kernel/signal.c:1242
 do_send_sig_info+0x9b/0xe0 kernel/signal.c:1291
 do_send_specific+0xc7/0x100 kernel/signal.c:3815
 do_tkill kernel/signal.c:3841 [inline]
 __do_sys_tgkill kernel/signal.c:3860 [inline]
 __se_sys_tgkill kernel/signal.c:3854 [inline]
 __x64_sys_tgkill+0x108/0x140 kernel/signal.c:3854
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 8439 Comm: syz-fuzzer Not tainted 5.11.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================