==================================================================
BUG: KCSAN: data-race in do_exit / zap_other_threads

read to 0xffff888121c4f534 of 4 bytes by task 19289 on cpu 1:
 zap_other_threads+0xaf/0x140 kernel/signal.c:1354
 do_group_exit+0x1b7/0x1c0 kernel/exit.c:890
 __do_sys_exit_group kernel/exit.c:906 [inline]
 __se_sys_exit_group kernel/exit.c:904 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:904
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff888121c4f534 of 4 bytes by task 19295 on cpu 0:
 exit_notify kernel/exit.c:676 [inline]
 do_exit+0xc0c/0x18c0 kernel/exit.c:818
 __do_sys_exit kernel/exit.c:864 [inline]
 __se_sys_exit kernel/exit.c:862 [inline]
 __x64_sys_exit+0x31/0x40 kernel/exit.c:862
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 19295 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 19295 Comm: syz-executor.0 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x11d/0x181 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xd kernel/kcsan/report.c:313
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:416
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_unaligned_write4+0xc7/0x110 kernel/kcsan/core.c:588
 exit_notify kernel/exit.c:676 [inline]
 do_exit+0xc0c/0x18c0 kernel/exit.c:818
 __do_sys_exit kernel/exit.c:864 [inline]
 __se_sys_exit kernel/exit.c:862 [inline]
 __x64_sys_exit+0x31/0x40 kernel/exit.c:862
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45b349
Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f0b94ffdc78 EFLAGS: 00000246 ORIG_RAX: 000000000000003c
RAX: ffffffffffffffda RBX: 00007f0b94ffe6d4 RCX: 000000000045b349
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000000a4 R14: 00000000004c1e62 R15: 000000000075bfd4
Kernel Offset: disabled
Rebooting in 86400 seconds..