syzbot


INFO: task hung in bch2_run_recovery_passes

Status: upstream: reported C repro on 2025/07/18 01:27
Subsystems: bcachefs
[Documentation on labels]
Reported-by: syzbot+c2294ae43bae606e3c7d@syzkaller.appspotmail.com
First crash: 48d, last: 1d23h
Cause bisection: introduced by (bisect log) :
commit 39cea302f13a0a9dc4cf39248529a42e79d06842
Author: Kent Overstreet <kent.overstreet@linux.dev>
Date: Fri May 9 21:01:05 2025 +0000

  bcachefs: bch2_check_bucket_backpointer_mismatch()

Crash: INFO: task hung in bch2_copygc_stop (log)
Repro: C syz .config
  
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [bcachefs?] INFO: task hung in bch2_run_recovery_passes 0 (3) 2025/07/30 04:17
Last patch testing requests (1)
Created Duration User Patch Repo Result
2025/08/14 09:22 22m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log

Sample crash report:
INFO: task syz-executor217:6018 blocked for more than 143 seconds.
      Tainted: G        W           6.17.0-rc1-syzkaller-00211-g90d970cade8e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor217 state:D stack:15112 pid:6018  tgid:6018  ppid:5837   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:268 [inline]
 __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 bch2_run_recovery_passes+0x177/0x210 fs/bcachefs/recovery_passes.c:609
 bch2_fs_recovery+0x28c9/0x3a50 fs/bcachefs/recovery.c:1050
 bch2_fs_start+0xaaf/0xda0 fs/bcachefs/super.c:1213
 bch2_fs_get_tree+0xb39/0x1520 fs/bcachefs/fs.c:2488
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4344 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4321
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbbf3d82b1a
RSP: 002b:00007ffcb1bb74e8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcb1bb7500 RCX: 00007fbbf3d82b1a
RDX: 00002000000000c0 RSI: 0000200000000000 RDI: 00007ffcb1bb7500
RBP: 0000200000000000 R08: 00007ffcb1bb7540 R09: 0000000000005934
R10: 0000000000810000 R11: 0000000000000282 R12: 00002000000000c0
R13: 00007ffcb1bb7540 R14: 0000000000000003 R15: 0000000000810000
 </TASK>
INFO: task syz-executor217:6105 blocked for more than 143 seconds.
      Tainted: G        W           6.17.0-rc1-syzkaller-00211-g90d970cade8e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor217 state:D stack:15112 pid:6105  tgid:6105  ppid:5838   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:268 [inline]
 __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 bch2_run_recovery_passes+0x177/0x210 fs/bcachefs/recovery_passes.c:609
 bch2_fs_recovery+0x28c9/0x3a50 fs/bcachefs/recovery.c:1050
 bch2_fs_start+0xaaf/0xda0 fs/bcachefs/super.c:1213
 bch2_fs_get_tree+0xb39/0x1520 fs/bcachefs/fs.c:2488
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4344 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4321
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbbf3d82b1a
RSP: 002b:00007ffcb1bb74e8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcb1bb7500 RCX: 00007fbbf3d82b1a
RDX: 00002000000000c0 RSI: 0000200000000000 RDI: 00007ffcb1bb7500
RBP: 0000200000000000 R08: 00007ffcb1bb7540 R09: 0000000000005934
R10: 0000000000810000 R11: 0000000000000282 R12: 00002000000000c0
R13: 00007ffcb1bb7540 R14: 0000000000000003 R15: 0000000000810000
 </TASK>
INFO: task syz-executor217:6315 blocked for more than 143 seconds.
      Tainted: G        W           6.17.0-rc1-syzkaller-00211-g90d970cade8e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor217 state:D stack:15112 pid:6315  tgid:6315  ppid:5840   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:268 [inline]
 __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 bch2_run_recovery_passes+0x177/0x210 fs/bcachefs/recovery_passes.c:609
 bch2_fs_recovery+0x28c9/0x3a50 fs/bcachefs/recovery.c:1050
 bch2_fs_start+0xaaf/0xda0 fs/bcachefs/super.c:1213
 bch2_fs_get_tree+0xb39/0x1520 fs/bcachefs/fs.c:2488
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4344 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4321
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbbf3d82b1a
RSP: 002b:00007ffcb1bb74e8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcb1bb7500 RCX: 00007fbbf3d82b1a
RDX: 00002000000000c0 RSI: 0000200000000000 RDI: 00007ffcb1bb7500
RBP: 0000200000000000 R08: 00007ffcb1bb7540 R09: 0000000000005934
R10: 0000000000810000 R11: 0000000000000282 R12: 00002000000000c0
R13: 00007ffcb1bb7540 R14: 0000000000000003 R15: 0000000000810000
 </TASK>
INFO: task syz-executor217:6417 blocked for more than 143 seconds.
      Tainted: G        W           6.17.0-rc1-syzkaller-00211-g90d970cade8e #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor217 state:D stack:15112 pid:6417  tgid:6417  ppid:5841   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75
 ___down_common kernel/locking/semaphore.c:268 [inline]
 __down_common+0x319/0x6a0 kernel/locking/semaphore.c:293
 down+0x80/0xd0 kernel/locking/semaphore.c:100
 bch2_run_recovery_passes+0x177/0x210 fs/bcachefs/recovery_passes.c:609
 bch2_fs_recovery+0x28c9/0x3a50 fs/bcachefs/recovery.c:1050
 bch2_fs_start+0xaaf/0xda0 fs/bcachefs/super.c:1213
 bch2_fs_get_tree+0xb39/0x1520 fs/bcachefs/fs.c:2488
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3805
 do_mount fs/namespace.c:4133 [inline]
 __do_sys_mount fs/namespace.c:4344 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4321
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbbf3d82b1a
RSP: 002b:00007ffcb1bb74e8 EFLAGS: 00000282 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ffcb1bb7500 RCX: 00007fbbf3d82b1a
RDX: 00002000000000c0 RSI: 0000200000000000 RDI: 00007ffcb1bb7500
RBP: 0000200000000000 R08: 00007ffcb1bb7540 R09: 0000000000005934
R10: 0000000000810000 R11: 0000000000000282 R12: 00002000000000c0
R13: 00007ffcb1bb7540 R14: 0000000000000003 R15: 0000000000810000
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G        W           6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:491
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Tainted: G        W           6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:io_serial_in+0x77/0xc0 drivers/tty/serial/8250/8250_port.c:400
Code: e8 ce d8 7f fc 44 89 f9 d3 e3 49 83 ee 80 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 cf 0b df fc 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 cc cc cc cc cc 44 89 f9 80 e1 07
RSP: 0018:ffffc90000167890 EFLAGS: 00000202
RAX: 1ffffffff3274800 RBX: 00000000000003fd RCX: 0000000000000000
RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffff993a4810 R08: 0000000000000000 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff853e8220 R12: dffffc0000000000
R13: 0000000000000000 R14: ffffffff993a4580 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881268c5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbbf3d7f633 CR3: 000000001e390000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 serial_in drivers/tty/serial/8250/8250.h:137 [inline]
 serial_lsr_in drivers/tty/serial/8250/8250.h:159 [inline]
 wait_for_lsr+0x1aa/0x2f0 drivers/tty/serial/8250/8250_port.c:1984
 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3288 [inline]
 serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3311 [inline]
 serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3396
 console_emit_next_record kernel/printk/printk.c:3118 [inline]
 console_flush_all+0x695/0xcd0 kernel/printk/printk.c:3226
 __console_flush_and_unlock+0xa4/0x240 kernel/printk/printk.c:3285
 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3638
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (34):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/17 08:30 upstream 90d970cade8e 1804e95e .config strace log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/07/29 18:19 upstream ae388edd4a8f c4a95487 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/09/02 11:36 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 807a3b61 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
2025/07/17 22:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci aaef6f251176 0d1223f1 .config console log report syz / log [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
2025/08/27 20:56 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/21 13:10 upstream 068a56e56fa8 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/21 12:26 upstream 068a56e56fa8 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/21 07:21 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/21 05:18 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/20 06:22 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/19 15:27 upstream be48bcf004f9 254a27c1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/18 18:09 upstream c17b750b3ad9 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/18 04:18 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/17 18:15 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/17 16:57 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/17 08:57 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/17 05:12 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/17 05:08 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bch2_run_recovery_passes
2025/08/17 00:02 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/16 15:26 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/16 12:52 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/16 07:38 upstream dfd4b508c8c6 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in bch2_run_recovery_passes
2025/08/16 01:55 upstream ee94b00c1a64 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/07/31 08:33 upstream e8d780dcd957 f8f2b4da .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/07/29 07:59 upstream ae388edd4a8f c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/07/29 07:57 upstream ae388edd4a8f c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/07/29 05:46 upstream ae388edd4a8f c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/07/29 04:07 upstream ae388edd4a8f 6654ea9c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: task hung in bch2_run_recovery_passes
2025/08/30 06:25 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
2025/08/20 09:04 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
2025/08/16 20:45 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
2025/07/25 04:55 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 82af5ea7c611 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
2025/07/20 09:12 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci aaef6f251176 7117feec .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
2025/07/17 12:06 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci aaef6f251176 0d1223f1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 INFO: task hung in bch2_run_recovery_passes
* Struck through repros no longer work on HEAD.