================================================================== BUG: KCSAN: data-race in mm_update_next_owner / wb_workfn write to 0xffff88812b7f40a4 of 4 bytes by task 21 on cpu 1: wb_workfn+0xcb/0x970 fs/fs-writeback.c:2067 process_one_work+0x424/0x930 kernel/workqueue.c:2264 worker_thread+0x9a/0x7e0 kernel/workqueue.c:2410 kthread+0x1cb/0x1f0 kernel/kthread.c:255 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352 read to 0xffff88812b7f40a4 of 4 bytes by task 25659 on cpu 0: mm_update_next_owner+0x376/0x5a0 kernel/exit.c:389 exit_mm kernel/exit.c:484 [inline] do_exit+0x638/0x1880 kernel/exit.c:788 do_group_exit+0xae/0x1a0 kernel/exit.c:899 __do_sys_exit_group kernel/exit.c:910 [inline] __se_sys_exit_group kernel/exit.c:908 [inline] __x64_sys_exit_group+0x2b/0x30 kernel/exit.c:908 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 25659 Comm: syz-executor.2 Not tainted 5.6.0-rc1-syzkaller #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: 25659 Comm: syz-executor.2 Not tainted 5.6.0-rc1-syzkaller #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+0x11d/0x187 lib/dump_stack.c:118 panic+0x210/0x640 kernel/panic.c:221 kcsan_report.cold+0xc/0xf kernel/kcsan/report.c:599 kcsan_setup_watchpoint+0x3fb/0x440 kernel/kcsan/core.c:507 mm_update_next_owner+0x376/0x5a0 kernel/exit.c:389 exit_mm kernel/exit.c:484 [inline] do_exit+0x638/0x1880 kernel/exit.c:788 do_group_exit+0xae/0x1a0 kernel/exit.c:899 __do_sys_exit_group kernel/exit.c:910 [inline] __se_sys_exit_group kernel/exit.c:908 [inline] __x64_sys_exit_group+0x2b/0x30 kernel/exit.c:908 do_syscall_64+0xc7/0x390 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c849 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:00007fff552681c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000001e RCX: 000000000045c849 RDX: 00000000004163e1 RSI: fffffffffffffff7 RDI: 0000000000000000 RBP: 0000000000000000 R08: 00000000e8ab10ac R09: 00007fff55268220 R10: 00000000e8ab10a8 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff55268220 R14: 0000000000000000 R15: 00007fff55268230 Kernel Offset: disabled Rebooting in 86400 seconds..