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

read to 0xffff8881153dd4a8 of 8 bytes by task 7492 on cpu 1:
 mm_update_next_owner+0x374/0x460 kernel/exit.c:454
 exit_mm kernel/exit.c:546 [inline]
 do_exit+0x4e5/0x18e0 kernel/exit.c:866
 do_group_exit+0xb4/0x1c0 kernel/exit.c:983
 __do_sys_exit_group kernel/exit.c:994 [inline]
 __se_sys_exit_group kernel/exit.c:992 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:992
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8881153dd4a8 of 8 bytes by task 7493 on cpu 0:
 exit_mm kernel/exit.c:542 [inline]
 do_exit+0x4b6/0x18e0 kernel/exit.c:866
 do_group_exit+0xb4/0x1c0 kernel/exit.c:983
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x3b/0xc00 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x2d7/0x2f0 arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7493 Comm: syz-executor.5 Not tainted 5.3.0+ #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: 7493 Comm: syz-executor.5 Not tainted 5.3.0+ #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+0x209/0x639 kernel/panic.c:219
 kcsan_report.cold+0xc/0x1b kernel/kcsan/report.c:303
 __kcsan_setup_watchpoint+0x3ee/0x510 kernel/kcsan/core.c:440
 __tsan_write8 kernel/kcsan/kcsan.c:31 [inline]
 __tsan_write8+0x32/0x40 kernel/kcsan/kcsan.c:31
 exit_mm kernel/exit.c:542 [inline]
 do_exit+0x4b6/0x18e0 kernel/exit.c:866
 do_group_exit+0xb4/0x1c0 kernel/exit.c:983
 get_signal+0x2a2/0x1320 kernel/signal.c:2734
 do_signal+0x3b/0xc00 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x250/0x2c0 arch/x86/entry/common.c:159
 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
 do_syscall_64+0x2d7/0x2f0 arch/x86/entry/common.c:299
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x459a59
Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f80b446acf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 000000000075bf28 RCX: 0000000000459a59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000075bf28
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf2c
R13: 00007ffcc9b42bcf R14: 00007f80b446b9c0 R15: 000000000075bf2c
Kernel Offset: disabled
Rebooting in 86400 seconds..