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KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (15)

Status: moderation: reported on 2025/06/02 21:14
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+c81b6ee731e9ce8df649@syzkaller.appspotmail.com
First crash: 51d, last: 14d
Similar bugs (14)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (3) fs 6 1 1015d 1015d 0/29 auto-obsoleted due to no activity on 2022/11/16 21:51
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (5) fs 6 2 821d 832d 0/29 auto-obsoleted due to no activity on 2023/05/30 05:48
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (7) ext4 6 3 647d 674d 0/29 auto-obsoleted due to no activity on 2023/11/20 11:49
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (9) fs 6 1 551d 551d 0/29 auto-obsoleted due to no activity on 2024/02/23 17:16
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (11) exfat 6 1 325d 325d 0/29 auto-obsoleted due to no activity on 2024/10/07 09:54
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (6) ext4 6 1 711d 711d 0/29 auto-obsoleted due to no activity on 2023/09/17 01:43
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (10) fs 6 1 467d 467d 0/29 auto-obsoleted due to no activity on 2024/05/17 23:40
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (13) ext4 6 2 222d 224d 0/29 auto-obsoleted due to no activity on 2025/02/08 00:12
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (2) fs 6 14 1060d 1266d 0/29 auto-closed as invalid on 2022/10/03 06:12
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (14) fs 6 1 120d 120d 0/29 auto-obsoleted due to no activity on 2025/05/20 16:51
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (8) ext4 6 1 602d 590d 0/29 auto-obsoleted due to no activity on 2024/01/04 10:47
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu ext4 6 137 1339d 1497d 0/29 auto-closed as invalid on 2021/12/28 13:59
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (12) fs 6 1 281d 281d 0/29 auto-obsoleted due to no activity on 2024/11/20 10:12
upstream KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu (4) ext4 6 3 926d 977d 0/29 auto-obsoleted due to no activity on 2023/03/11 22:09

Sample crash report:
EXT4-fs (loop9): unmounting filesystem 00000000-0000-0000-0000-000000000000.
==================================================================
BUG: KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu

write to 0xffff888237c26f10 of 8 bytes by task 24584 on cpu 0:
 __invalidate_bh_lrus fs/buffer.c:1535 [inline]
 invalidate_bh_lrus_cpu+0x89/0xc0 fs/buffer.c:1580
 lru_add_and_bh_lrus_drain mm/swap.c:746 [inline]
 lru_add_drain_per_cpu+0x55/0x70 mm/swap.c:765
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0x4cb/0x9d0 kernel/workqueue.c:3321
 worker_thread+0x582/0x770 kernel/workqueue.c:3402
 kthread+0x489/0x510 kernel/kthread.c:464
 ret_from_fork+0xda/0x150 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff888237c26f10 of 8 bytes by task 23759 on cpu 1:
 has_bh_in_lru+0x35/0x1f0 fs/buffer.c:1557
 smp_call_function_many_cond+0x38c/0xbf0 kernel/smp.c:838
 on_each_cpu_cond_mask+0x3c/0x80 kernel/smp.c:1052
 on_each_cpu_cond include/linux/smp.h:105 [inline]
 invalidate_bh_lrus+0x2a/0x30 fs/buffer.c:1566
 invalidate_bdev+0x42/0x70 block/bdev.c:100
 ext4_put_super+0x624/0x7d0 fs/ext4/super.c:1339
 generic_shutdown_super+0xe6/0x210 fs/super.c:643
 kill_block_super+0x2a/0x70 fs/super.c:1755
 ext4_kill_sb+0x42/0x80 fs/ext4/super.c:7391
 deactivate_locked_super+0x72/0x1c0 fs/super.c:474
 deactivate_super+0x97/0xa0 fs/super.c:507
 cleanup_mnt+0x269/0x2e0 fs/namespace.c:1417
 __cleanup_mnt+0x19/0x20 fs/namespace.c:1424
 task_work_run+0x131/0x1a0 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xe4/0x100 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x1d6/0x200 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0xffff888100462bc8 -> 0x0000000000000000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 23759 Comm: syz-executor Tainted: G        W           6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(voluntary) 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
==================================================================

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/10 15:10 upstream 8c2e52ebbe88 956bd956 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu
2025/07/04 01:13 upstream 17bbde2e1716 76ad128c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu
2025/06/27 18:55 upstream 67a993863163 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu
2025/06/02 21:14 upstream cd2e103d57e5 b396b4bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-kcsan-gce KCSAN: data-race in has_bh_in_lru / invalidate_bh_lrus_cpu
* Struck through repros no longer work on HEAD.