==================================================================
BUG: KCSAN: data-race in exit_signals / mm_update_next_owner

read to 0xffff8880aa0e1024 of 4 bytes by task 18673 on cpu 0:
 mm_update_next_owner+0x29f/0x460 kernel/exit.c:389
 exit_mm kernel/exit.c:484 [inline]
 do_exit+0x4c1/0x18f0 kernel/exit.c:804
 do_group_exit+0xb4/0x1c0 kernel/exit.c:921
 __do_sys_exit_group kernel/exit.c:932 [inline]
 __se_sys_exit_group kernel/exit.c:930 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:930
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880aa0e1024 of 4 bytes by task 18670 on cpu 1:
 exit_signals+0x13b/0x490 kernel/signal.c:2822
 do_exit+0x18b/0x18f0 kernel/exit.c:763
 do_group_exit+0xb4/0x1c0 kernel/exit.c:921
 __do_sys_exit_group kernel/exit.c:932 [inline]
 __se_sys_exit_group kernel/exit.c:930 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:930
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 18670 Comm: syz-executor.1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 18670 Comm: syz-executor.1 Not tainted 5.4.0-rc3+ #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+0xf5/0x159 lib/dump_stack.c:113
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0x10 kernel/kcsan/report.c:302
 __kcsan_setup_watchpoint+0x32e/0x4a0 kernel/kcsan/core.c:411
 __tsan_write4 kernel/kcsan/kcsan.c:35 [inline]
 __tsan_write4+0x32/0x40 kernel/kcsan/kcsan.c:35
 exit_signals+0x13b/0x490 kernel/signal.c:2822
 do_exit+0x18b/0x18f0 kernel/exit.c:763
 do_group_exit+0xb4/0x1c0 kernel/exit.c:921
 __do_sys_exit_group kernel/exit.c:932 [inline]
 __se_sys_exit_group kernel/exit.c:930 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:930
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x459f49
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:00007ffec5c190a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 0000000000459f49
RDX: 0000000000413ae1 RSI: fffffffffffffff7 RDI: 0000000000000000
RBP: 0000000000000000 R08: 00000000f559b6b3 R09: 00007ffec5c19100
R10: ffffffff81006bd0 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffec5c19100 R14: 0000000000000000 R15: 00007ffec5c19110
Kernel Offset: disabled
Rebooting in 86400 seconds..