syzbot


WARNING in bch2_fs_btree_iter_exit

Status: upstream: reported C repro on 2025/06/11 12:36
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+1a64e5e20993a6c1a9f2@syzkaller.appspotmail.com
First crash: 7d03h, last: 7d03h
Discussions (1)
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[syzbot] [bcachefs?] WARNING in bch2_fs_btree_iter_exit 0 (1) 2025/06/11 12:36

Sample crash report:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6496 at kernel/rcu/srcutree.c:695 cleanup_srcu_struct+0x420/0x504 kernel/rcu/srcutree.c:718
Modules linked in:
CPU: 0 UID: 0 PID: 6496 Comm: syz-executor216 Not tainted 6.15.0-rc7-syzkaller-gd7fa1af5b33e #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : cleanup_srcu_struct+0x420/0x504 kernel/rcu/srcutree.c:718
lr : cleanup_srcu_struct+0x2b8/0x504 kernel/rcu/srcutree.c:694
sp : ffff8000a4f079b0
x29: ffff8000a4f079d0 x28: 1ffff00011d84e4b x27: 1fffe0001da80844
x26: ffff80008ec27000 x25: dfff800000000000 x24: fffffdffbf7693c8
x23: fffffdffbf769300 x22: ffff0000ed404220 x21: ffffffffffffffff
x20: ffff80008f321e88 x19: 0000000000000001 x18: 1fffe0003386aa76
x17: ffff80008f31e000 x16: ffff80008adbeaf4 x15: 0000000000000001
x14: 1fffffbff7eed28c x13: 0000000000000000 x12: 0000000000000000
x11: ffff7fbff7eed28d x10: 0000000000ff0100 x9 : 96b044024d34f400
x8 : 0000000000000006 x7 : ffff800080433050 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080422d24
x2 : 0000000000000000 x1 : 0000000000000080 x0 : 0000000000000000
Call trace:
 cleanup_srcu_struct+0x420/0x504 kernel/rcu/srcutree.c:718 (P)
 bch2_fs_btree_iter_exit+0x380/0x420 fs/bcachefs/btree_iter.c:3617
 __bch2_fs_free fs/bcachefs/super.c:564 [inline]
 bch2_fs_release+0x24c/0x72c fs/bcachefs/super.c:618
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x2b0/0x438 lib/kobject.c:737
 bch2_fs_free+0x308/0x378 fs/bcachefs/super.c:681
 bch2_kill_sb+0x48/0x58 fs/bcachefs/fs.c:2623
 deactivate_locked_super+0xc4/0x12c fs/super.c:473
 deactivate_super+0xe0/0x100 fs/super.c:506
 cleanup_mnt+0x31c/0x3ac fs/namespace.c:1431
 __cleanup_mnt+0x20/0x30 fs/namespace.c:1438
 task_work_run+0x1dc/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 do_notify_resume+0x16c/0x1ec arch/arm64/kernel/entry-common.c:151
 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:169 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:178 [inline]
 el0_svc+0xb4/0x17c arch/arm64/kernel/entry-common.c:768
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:786
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
irq event stamp: 324162
hardirqs last  enabled at (324161): [<ffff80008addfa48>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
hardirqs last  enabled at (324161): [<ffff80008addfa48>] _raw_spin_unlock_irqrestore+0x38/0x98 kernel/locking/spinlock.c:194
hardirqs last disabled at (324162): [<ffff80008adb9eb8>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:511
softirqs last  enabled at (322512): [<ffff8000803cf71c>] softirq_handle_end kernel/softirq.c:425 [inline]
softirqs last  enabled at (322512): [<ffff8000803cf71c>] handle_softirqs+0xaf8/0xc88 kernel/softirq.c:607
softirqs last disabled at (322371): [<ffff800080020efc>] __do_softirq+0x14/0x20 kernel/softirq.c:613
---[ end trace 0000000000000000 ]---
bcachefs (loop4): shutting down
bcachefs (loop4): going read-only
bcachefs (loop4): finished waiting for writes to stop
bcachefs (loop4): flushing journal and stopping allocators, journal seq 3
bcachefs (loop4): flushing journal and stopping allocators complete, journal seq 3
bcachefs (loop4): clean shutdown complete, journal seq 4
bcachefs (loop4): marking filesystem clean
bcachefs (loop4): shutdown complete

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/09 13:36 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci d7fa1af5b33e 4826c28e .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1] [mounted in repro #2] ci-upstream-gce-arm64 WARNING in bch2_fs_btree_iter_exit
* Struck through repros no longer work on HEAD.