syzbot


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

Status: auto-closed as invalid on 2021/01/13 07:05
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+c011c9a099437b856992@syzkaller.appspotmail.com
First crash: 1288d, last: 1242d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in kcompactd / mm_update_next_owner mm 1 1342d 1342d 0/26 auto-closed as invalid on 2020/10/05 21:28

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

read-write to 0xffff8881018a3024 of 4 bytes by task 1656 on cpu 1:
 freezer_do_not_count include/linux/freezer.h:109 [inline]
 freezable_schedule_timeout include/linux/freezer.h:191 [inline]
 kcompactd+0x366/0xde0 mm/compaction.c:2818
 kthread+0x1fd/0x220 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

read to 0xffff8881018a3024 of 4 bytes by task 12599 on cpu 0:
 mm_update_next_owner+0x1d9/0x4e0 kernel/exit.c:387
 exit_mm+0x2ff/0x370 kernel/exit.c:485
 do_exit+0x3c8/0x1630 kernel/exit.c:796
 do_group_exit+0xc8/0x170 kernel/exit.c:906
 get_signal+0xf9b/0x1510 kernel/signal.c:2758
 arch_do_signal+0x25/0x260 arch/x86/kernel/signal.c:811
 exit_to_user_mode_loop kernel/entry/common.c:161 [inline]
 exit_to_user_mode_prepare+0xde/0x170 kernel/entry/common.c:191
 syscall_exit_to_user_mode+0x16/0x30 kernel/entry/common.c:266
 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: 0 PID: 12599 Comm: syz-executor.3 Not tainted 5.10.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/12/09 07:04 upstream 7d8761ba27fc 40cc414d .config console log report info ci2-upstream-kcsan-gce
2020/12/01 17:40 upstream b65054597872 07bfe8a5 .config console log report info ci2-upstream-kcsan-gce
2020/11/22 14:55 upstream a349e4c65960 0d27f508 .config console log report info ci2-upstream-kcsan-gce
2020/10/24 05:57 upstream 0adc313c4f20 2bb6666c .config console log report info ci2-upstream-kcsan-gce
* Struck through repros no longer work on HEAD.