================================================================== BUG: KCSAN: data-race in mm_update_next_owner / stop_this_handle write to 0xffff88813656b02c of 4 bytes by task 10065 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_dirty_inode+0x9a/0xa0 fs/ext4/inode.c:5945 __mark_inode_dirty+0x72/0x6f0 fs/fs-writeback.c:2274 generic_update_time fs/inode.c:1765 [inline] update_time fs/inode.c:1778 [inline] file_update_time+0x3a4/0x3e0 fs/inode.c:1993 ext4_page_mkwrite+0x146/0xf50 fs/ext4/inode.c:6061 do_page_mkwrite mm/memory.c:2726 [inline] do_shared_fault+0x218/0x680 mm/memory.c:4005 do_fault mm/memory.c:4073 [inline] handle_pte_fault mm/memory.c:4320 [inline] __handle_mm_fault mm/memory.c:4455 [inline] handle_mm_fault+0x12f0/0x18a0 mm/memory.c:4553 do_user_addr_fault+0x60c/0xc00 arch/x86/mm/fault.c:1384 handle_page_fault arch/x86/mm/fault.c:1469 [inline] exc_page_fault+0x94/0x2a0 arch/x86/mm/fault.c:1525 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:580 read to 0xffff88813656b02c of 4 bytes by task 10070 on cpu 1: mm_update_next_owner+0x1d9/0x4e0 kernel/exit.c:388 exit_mm+0x33c/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:208 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline] syscall_exit_to_user_mode+0x20/0x40 kernel/entry/common.c:301 do_syscall_64+0x45/0x80 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x44/0xae Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 10070 Comm: syz-executor.5 Not tainted 5.11.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ==================================================================