syzbot

==================================================================
BUG: KCSAN: data-race in kernel_clone / mm_release

write to 0xffff888140513600 of 8 bytes by task 18007 on cpu 1:
 wait_for_vfork_done kernel/fork.c:1287 [inline]
 kernel_clone+0x345/0x680 kernel/fork.c:2540
 __do_sys_clone kernel/fork.c:2626 [inline]
 __se_sys_clone kernel/fork.c:2610 [inline]
 __x64_sys_clone+0xb4/0xe0 kernel/fork.c:2610
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff888140513600 of 8 bytes by task 18013 on cpu 0:
 mm_release+0x14d/0x200 kernel/fork.c:1338
 exit_mm_release+0x21/0x30 kernel/fork.c:1345
 exit_mm+0x4b/0x3f0 kernel/exit.c:439
 do_exit+0x402/0x1530 kernel/exit.c:812
 do_group_exit+0xa4/0x1a0 kernel/exit.c:922
 __do_sys_exit_group+0xb/0x10 kernel/exit.c:933
 __se_sys_exit_group+0x5/0x10 kernel/exit.c:931
 __x64_sys_exit_group+0x16/0x20 kernel/exit.c:931
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffc9000b273e30 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 18013 Comm: syz-executor.3 Not tainted 5.14.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================