syzbot


KCSAN: data-race in mm_update_next_owner / wb_workfn (2)

Status: auto-closed as invalid on 2020/06/08 08:14
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 959d, last: 869d
similar bugs (7):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in mm_update_next_owner / wb_workfn (4) 1 673d 673d 0/23 auto-closed as invalid on 2020/11/16 07:19
upstream KCSAN: data-race in mm_update_next_owner / wb_workfn (7) 1 521d 521d 0/23 auto-closed as invalid on 2021/04/17 00:26
upstream KCSAN: data-race in mm_update_next_owner / wb_workfn (3) 2 759d 779d 0/23 auto-closed as invalid on 2020/08/22 21:27
upstream KCSAN: data-race in mm_update_next_owner / wb_workfn (5) 2 613d 617d 0/23 auto-closed as invalid on 2021/01/15 21:05
upstream KCSAN: data-race in mm_update_next_owner / wb_workfn (6) 2 565d 577d 0/23 auto-closed as invalid on 2021/03/04 08:19
upstream KCSAN: data-race in mm_update_next_owner / wb_workfn (8) 4 452d 462d 0/23 auto-closed as invalid on 2021/06/25 06:02
upstream KCSAN: data-race in mm_update_next_owner / wb_workfn 2 1012d 1023d 0/23 closed as invalid on 2019/11/19 14:44

Sample crash report:
==================================================================
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..

Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2020/03/30 08:05 https://github.com/google/ktsan.git kcsan 40959e34d670 05736b29 .config log report
ci2-upstream-kcsan-gce 2020/02/13 02:38 https://github.com/google/ktsan.git kcsan f60f0f543333 84f4fc8a .config log report
ci2-upstream-kcsan-gce 2019/12/31 11:41 https://github.com/google/ktsan.git kcsan 245a43005292 7f117e28 .config log report