syzbot


INFO: task hung in sync_bdevs (3)

Status: upstream: reported C repro on 2025/02/23 13:57
Subsystems: block
[Documentation on labels]
Reported-by: syzbot+97bc0b256218ed6df337@syzkaller.appspotmail.com
First crash: 213d, last: 7h00m
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly block report (Aug 2025) 0 (1) 2025/08/27 08:15
[syzbot] [block?] INFO: task hung in sync_bdevs (3) 0 (2) 2025/08/15 22:41
[syzbot] Monthly block report (Jul 2025) 0 (1) 2025/07/27 10:41
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 INFO: task hung in sync_bdevs 1 6 13d 30d 0/3 upstream: reported on 2025/07/29 07:59
upstream INFO: task hung in sync_bdevs (2) block 1 1 305d 305d 0/29 auto-obsoleted due to no activity on 2025/01/25 03:29
linux-5.15 INFO: task hung in sync_bdevs 1 1 462d 462d 0/3 auto-obsoleted due to no activity on 2024/08/31 17:12
upstream INFO: task hung in sync_bdevs block 1 5 844d 1048d 0/29 auto-obsoleted due to no activity on 2023/08/05 18:35
linux-6.6 INFO: task hung in sync_bdevs 1 18 5d11h 50d 0/2 upstream: reported on 2025/07/09 10:03

Sample crash report:
INFO: task syz-executor297:5890 blocked for more than 143 seconds.
      Not tainted 6.17.0-rc1-next-20250814-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor297 state:D stack:28168 pid:5890  tgid:5890  ppid:5887   task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e6/0x1360 kernel/locking/mutex.c:760
 sync_bdevs+0x1ac/0x340 block/bdev.c:1288
 ksys_sync+0xb9/0x150 fs/sync.c:105
 __ia32_sys_sync+0xe/0x20 fs/sync.c:113
 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: 0033:0x7fd97a9d2959
RSP: 002b:00007ffd0221b4d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd97a9d2959
RDX: 00007fd97a9d1b90 RSI: 0000000000000012 RDI: 00007fd97aa1b03b
RBP: 000000000002219f R08: 0000000000000000 R09: 0000000000000006
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd0221b4ec
R13: 431bde82d7b634db R14: 0000000000000001 R15: 0000000000000001
 </TASK>
INFO: lockdep is turned off.
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) 
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:332 [inline]
 watchdog+0xf60/0xfa0 kernel/hung_task.c:495
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3f9/0x770 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: 0 Comm: swapper/0 Not tainted 6.17.0-rc1-next-20250814-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: 53 e8 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 33 1a 25 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8e207d80 EFLAGS: 000002c6
RAX: 302944256c608e00 RBX: ffffffff8196d368 RCX: 302944256c608e00
RDX: 0000000000000001 RSI: ffffffff8c04d960 RDI: ffffffff8196d368
RBP: ffffffff8e207eb8 R08: ffff8880b8632f9b R09: 1ffff110170c65f3
R10: dffffc0000000000 R11: ffffed10170c65f4 R12: ffffffff8fe4db30
R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c52a40
FS:  0000000000000000(0000) GS:ffff8881257d6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005595b06bc168 CR3: 000000000e336000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e8/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 rest_init+0x2de/0x300 init/main.c:756
 start_kernel+0x3a9/0x410 init/main.c:1109
 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x147
 </TASK>

Crashes (752):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/15 22:40 linux-next 931e46dcbc7e 1804e95e .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in sync_bdevs
2025/08/28 18:57 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/28 17:21 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/28 13:18 upstream 07d9df80082b 443c11c7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/28 07:53 upstream 39f90c196721 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/26 16:23 upstream fab1beda7597 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/26 03:01 upstream b6add54ba618 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/25 16:46 upstream b6add54ba618 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/24 15:09 upstream 8d245acc1e88 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/23 17:51 upstream 6debb6904172 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/23 02:22 upstream a2e94e80790b bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/23 01:08 upstream a2e94e80790b bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/22 22:02 upstream a2e94e80790b bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/22 20:32 upstream a2e94e80790b bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/21 15:37 upstream 32b7144f806e 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/21 12:45 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/21 08:52 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/21 06:18 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/21 03:27 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/21 02:26 upstream 41cd3fd15263 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/20 20:05 upstream b19a97d57c15 bd178e57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/20 12:08 upstream b19a97d57c15 bd178e57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/20 09:20 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/20 05:42 upstream b19a97d57c15 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/19 20:01 upstream b19a97d57c15 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/19 17:27 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/19 15:19 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/19 13:54 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/19 11:45 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/19 10:37 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/19 06:53 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/19 05:07 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/19 03:43 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/19 03:43 upstream be48bcf004f9 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/18 20:47 upstream c17b750b3ad9 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/18 18:22 upstream 038d61fd6422 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in sync_bdevs
2025/08/18 15:56 upstream c17b750b3ad9 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/18 08:47 upstream 8d561baae505 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/08/18 07:05 upstream 038d61fd6422 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in sync_bdevs
2025/08/18 05:43 upstream 038d61fd6422 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in sync_bdevs
2025/08/18 02:59 upstream 038d61fd6422 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in sync_bdevs
2025/02/23 13:55 upstream 27102b38b8ca d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: task hung in sync_bdevs
2025/02/19 13:47 upstream 6537cfb395f3 9a14138f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in sync_bdevs
2025/02/06 13:28 upstream 92514ef226f5 577d049b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in sync_bdevs
2025/08/26 11:57 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/25 12:26 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/24 10:25 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/23 16:17 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/22 12:23 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/21 07:26 linux-next 5303936d609e 0b9605c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in sync_bdevs
2025/08/20 14:37 linux-next 5303936d609e bd178e57 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in sync_bdevs
2025/08/20 11:02 linux-next 5303936d609e 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in sync_bdevs
2025/08/20 06:47 linux-next 5303936d609e 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/19 22:43 linux-next 886e5e7b0432 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in sync_bdevs
2025/08/19 08:28 linux-next 886e5e7b0432 523f460e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/18 23:15 linux-next 3ac864c2d9bb 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in sync_bdevs
2025/08/18 22:11 linux-next 3ac864c2d9bb 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in sync_bdevs
2025/08/18 19:46 linux-next 3ac864c2d9bb 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/18 04:48 linux-next 931e46dcbc7e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: task hung in sync_bdevs
2025/08/16 00:08 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 sync_bdevs
* Struck through repros no longer work on HEAD.