syzbot


KCSAN: data-race in mm_update_next_owner / wb_workfn

Status: closed as invalid on 2019/11/19 14:44
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1023d, last: 1012d
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 758d 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 (2) 3 869d 959d 0/23 auto-closed as invalid on 2020/06/08 08:14
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

Sample crash report:
==================================================================
BUG: KCSAN: data-race in mm_update_next_owner / wb_workfn

write to 0xffff88812af30024 of 4 bytes by task 2644 on cpu 0:
 wb_workfn+0xbf/0x970 fs/fs-writeback.c:2064
 process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
 worker_thread+0xa0/0x800 kernel/workqueue.c:2415
 kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

read to 0xffff88812af30024 of 4 bytes by task 15371 on cpu 1:
 mm_update_next_owner+0x29f/0x460 kernel/exit.c:389
 exit_mm kernel/exit.c:484 [inline]
 do_exit+0x4c1/0x18f0 kernel/exit.c:804
 do_group_exit+0xb4/0x1c0 kernel/exit.c:921
 __do_sys_exit_group kernel/exit.c:932 [inline]
 __se_sys_exit_group kernel/exit.c:930 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:930
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 15371 Comm: syz-executor.2 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 15371 Comm: syz-executor.2 Not tainted 5.4.0-rc6+ #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+0xf5/0x159 lib/dump_stack.c:113
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xe kernel/kcsan/report.c:302
 kcsan_setup_watchpoint+0x3fe/0x410 kernel/kcsan/core.c:357
 check_access kernel/kcsan/core.c:409 [inline]
 __tsan_read4+0x145/0x1f0 kernel/kcsan/core.c:529
 mm_update_next_owner+0x29f/0x460 kernel/exit.c:389
 exit_mm kernel/exit.c:484 [inline]
 do_exit+0x4c1/0x18f0 kernel/exit.c:804
 do_group_exit+0xb4/0x1c0 kernel/exit.c:921
 __do_sys_exit_group kernel/exit.c:932 [inline]
 __se_sys_exit_group kernel/exit.c:930 [inline]
 __x64_sys_exit_group+0x2e/0x30 kernel/exit.c:930
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45a219
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:00007ffcb5d92d48 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 000000000045a219
RDX: 0000000000413db1 RSI: fffffffffffffff7 RDI: 0000000000000000
RBP: 0000000000000000 R08: ffffffffffffffff R09: 00007ffcb5d92da0
R10: 00000000f2b90448 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffcb5d92da0 R14: 0000000000000000 R15: 00007ffcb5d92db0
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-upstream-kcsan-gce 2019/11/08 02:30 https://github.com/google/ktsan.git kcsan 94c006602e13 f39aff9e .config log report
ci2-upstream-kcsan-gce 2019/10/28 16:40 https://github.com/google/ktsan.git kcsan 05f2236801fe 439d7b14 .config log report