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

write to 0xffff888036fad02c of 4 bytes by task 19258 on cpu 0:
 memalloc_nofs_restore include/linux/sched/mm.h:258 [inline]
 stop_this_handle+0x2ae/0x2f0 fs/jbd2/transaction.c:744
 jbd2_journal_stop+0x573/0x6d0 fs/jbd2/transaction.c:1907
 __ext4_journal_stop+0x99/0x110 fs/ext4/ext4_jbd2.c:127
 ext4_symlink+0x559/0x780 fs/ext4/namei.c:3408
 vfs_symlink+0x216/0x2d0 fs/namei.c:3962
 do_symlinkat+0xee/0x280 fs/namei.c:3989
 __do_sys_symlink fs/namei.c:4008 [inline]
 __se_sys_symlink fs/namei.c:4006 [inline]
 __x64_sys_symlink+0x32/0x40 fs/namei.c:4006
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888036fad02c of 4 bytes by task 19257 on cpu 1:
 mm_update_next_owner+0x1d9/0x4e0 kernel/exit.c:388
 exit_mm+0x337/0x430 kernel/exit.c:500
 do_exit+0x41f/0x1690 kernel/exit.c:812
 do_group_exit+0xce/0x180 kernel/exit.c:922
 get_signal+0xdce/0x14e0 kernel/signal.c:2773
 arch_do_signal_or_restart+0x2a/0x270 arch/x86/kernel/signal.c:811
 handle_signal_work kernel/entry/common.c:147 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
 exit_to_user_mode_prepare+0x11a/0x1b0 kernel/entry/common.c:201
 __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline]
 syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:294
 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19257 Comm: syz-executor.5 Not tainted 5.11.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================