syzbot


INFO: task hung in process_one_work (5)

Status: upstream: reported C repro on 2026/01/23 22:30
Subsystems: f2fs
[Documentation on labels]
Reported-by: syzbot+5dd7feff22865a110a30@syzkaller.appspotmail.com
First crash: 156d, last: 61d
✨ AI Jobs (5)
ID Workflow Result Correct Bug Created Started Finished Revision Error
a8f789c6-5c88-430f-ab57-c71f905d33ab assessment-security 💥 INFO: task hung in process_one_work (5) 2026/06/18 09:09 2026/06/18 09:09 2026/06/18 09:09 b62b3ded1759f79b37600c5ffe2b0a81b919b0b0
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "59e4d31a0470503dc922bad1970fc6a1c7dfd76b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
cce340e6-f17c-4b60-9ca2-fea8d8674935 assessment-security 💥 INFO: task hung in process_one_work (5) 2026/06/10 04:57 2026/06/10 04:57 2026/06/10 04:57 c36c07f6c1f2230a36374cbd22235f635e8f9284
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "59e4d31a0470503dc922bad1970fc6a1c7dfd76b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
d529c826-5020-4305-8869-5367087b0be4 assessment-security 💥 INFO: task hung in process_one_work (5) 2026/06/04 08:33 2026/06/04 08:33 2026/06/04 08:33 62fe15281f5011cd203d8845b8767b10e7443aa5
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "59e4d31a0470503dc922bad1970fc6a1c7dfd76b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
11506d2a-67e0-4977-b49a-ff6240be7fc0 assessment-security 💥 INFO: task hung in process_one_work (5) 2026/06/02 07:37 2026/06/02 07:37 2026/06/02 07:37 1095583bae1d2729a3b4be301cb6ddc85ced9e38
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "59e4d31a0470503dc922bad1970fc6a1c7dfd76b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
26d109b2-1012-42f0-8e3c-196a32958fe0 assessment-security 💥 INFO: task hung in process_one_work (5) 2026/05/23 01:02 2026/05/23 01:02 2026/05/23 01:02 df8ac09c914d5408499c5695877a3e0e31969e6f
failed to run ["git" "-c" "core.hooksPath=/dev/null" "fetch" "--force" "--tags" "433dfd5a8a5d80bbf0669b14e9ed908911a52dd6" "59e4d31a0470503dc922bad1970fc6a1c7dfd76b"]: exit status 128
fatal: remote er...
truncated to first 200 bytes; open job for full error
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [f2fs?] INFO: task hung in process_one_work (5) 0 (1) 2026/01/23 22:30
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in process_one_work trace 1 1 2998d 2998d 0/29 auto-closed as invalid on 2019/02/22 10:22
upstream INFO: task hung in process_one_work (4) wireguard 1 syz error error 53 609d 2134d 0/29 auto-obsoleted due to no activity on 2025/01/31 08:54
upstream INFO: task hung in process_one_work (3) net 1 1 2399d 2399d 0/29 closed as invalid on 2019/11/30 16:54
upstream INFO: task hung in process_one_work (2) net bpf 1 1 2563d 2563d 0/29 auto-closed as invalid on 2019/10/25 10:51
Last patch testing requests (7)
Created Duration User Patch Repo Result
2026/06/24 10:16 3h39m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2026/06/24 09:26 31m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2026/04/15 09:14 1h01m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/04/15 07:49 53m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/04/15 07:49 54m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/02/04 03:03 37m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/02/04 03:03 38m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error

Sample crash report:
INFO: task kworker/1:0:32 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0     state:D stack:22080 pid:32    tgid:32    ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x169e/0x54f0 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563
 rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1662
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline]
 __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1779 [inline]
 rt_mutex_slowlock+0x2dc/0x780 kernel/locking/rtmutex.c:1819
 __rt_mutex_lock kernel/locking/rtmutex.c:1834 [inline]
 __mutex_lock_common kernel/locking/rtmutex_api.c:535 [inline]
 mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:553
 hub_even[  407.202529][   T39]  hub_port_connect drivers/usb/core/hub.c:5465 [inline]
 hub_even[  407.202529][   T39]  hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 hub_even[  407.202529][   T39]  port_event drivers/usb/core/hub.c:5871 [inline]
 hub_even[  407.202529][   T39]  hub_event+0x21e0/0x4f60 drivers/usb/core/hub.c:5953
 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312
 process_scheduled_works kernel/workqueue.c:3403 [inline]
 worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/1:0/32:
 #0: ffff88801b379538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284
 #1: ffffc90000a6fc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285
 #2: ffff88802bfc4210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #2: ffff88802bfc4210 (&dev->mutex){....}-{4:4}, at: hub_event+0x17c/0x4f60 drivers/usb/core/hub.c:5899
 #3: ffff88802bf84658 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
 #3: ffff88802bf84658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
 #3: ffff88802bf84658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #3: ffff88802bf84658 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #3: ffff88802bf84658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b0/0x4f60 drivers/usb/core/hub.c:5953
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e0/0x4f60 drivers/usb/core/hub.c:5953
1 lock held by khungtaskd/39:
 #0: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6777
5 locks held by kworker/0:2/822:
 #0: ffff88801b379538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284
 #1: ffffc90005457c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285
 #2: ffff88802bf20210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline]
 #2: ffff88802bf20210 (&dev->mutex){....}-{4:4}, at: hub_event+0x17c/0x4f60 drivers/usb/core/hub.c:5899
 #3: ffff88802bf61658 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline]
 #3: ffff88802bf61658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline]
 #3: ffff88802bf61658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #3: ffff88802bf61658 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #3: ffff88802bf61658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x21b0/0x4f60 drivers/usb/core/hub.c:5953
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline]
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline]
 #4: ffff88802b0ca058 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x21e0/0x4f60 drivers/usb/core/hub.c:5953
5 locks held by kworker/u8:9/1043:
 #0: ffff888033eef938 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284
 #1: ffffc900056b7c40 ((work_completion)(&(&bat_priv->dat.work)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285
 #2: ffffffff8e25f340 (local_bh){.+.+}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
 #3: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: __local_bh_disable_ip+0x3c/0x420 kernel/softirq.c:163
 #4: ffff88805839f558 (&hash->list_locks[i]){+...}-{3:3}, at: spin_lock_bh include/linux/spinlock_rt.h:90 [inline]
 #4: ffff88805839f558 (&hash->list_locks[i]){+...}-{3:3}, at: __batadv_dat_purge+0x131/0x400 net/batman-adv/distributed-arp-table.c:173
4 locks held by kworker/u8:11/1184:
 #0: ffff88801be86138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x890/0x1710 kernel/workqueue.c:3284
 #1: ffffc90005ecfc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x8b7/0x1710 kernel/workqueue.c:3285
 #2: ffffffff8f795000 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:673
 #3: ffffffff8e3ce3b0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828
1 lock held by dhcpcd/5493:
 #0: ffffffff8f7a44b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline]
 #0: ffffffff8f7a44b8 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120
2 locks held by getty/5583:
 #0: ffff8880380f50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003cae2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211
4 locks held by syz-executor/10325:
 #0: ffffffff8eef59c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #0: ffffffff8eef59c8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8eef59c8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
 #1: ffffffff8f7a44b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
 #1: ffffffff8f7a44b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
 #1: ffffffff8f7a44b8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4108
 #2: ffff8880b8746510 ((&pcs->lock)){+.+.}-{3:3}, at: alloc_from_pcs mm/slub.c:4743 [inline]
 #2: ffff8880b8746510 ((&pcs->lock)){+.+.}-{3:3}, at: slab_alloc_node mm/slub.c:4883 [inline]
 #2: ffff8880b8746510 ((&pcs->lock)){+.+.}-{3:3}, at: kmem_cache_alloc_node_noprof+0x304/0x6e0 mm/slub.c:4950
 #3: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 #3: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #3: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: __rt_spin_trylock kernel/locking/spinlock_rt.c:110 [inline]
 #3: ffffffff8e3c81c0 (rcu_read_lock){....}-{1:3}, at: rt_spin_trylock+0x10c/0x2b0 kernel/locking/spinlock_rt.c:118

=============================================

NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x135/0x170 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline]
 watchdog+0xfd3/0x1030 kernel/hung_task.c:561
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 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: 1043 Comm: kworker/u8:9 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x3a/0xb0 kernel/rcu/tree.c:752
Code: e8 0b 10 99 09 89 c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 90 b7 c4 8d 4c 89 f0 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 f7 e8 7c 7d 84 00 48 c7 c3 98 8e bd 92 49 03 1e 48 89
RSP: 0018:ffffc900056b7a48 EFLAGS: 00000046
RAX: 1ffffffff1b896f2 RBX: 0000000000000000 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8bca7040 RDI: ffffffff8bca7000
RBP: 0000000000000400 R08: ffffffff8fcf67f7 R09: 1ffffffff1f9ecfe
R10: dffffc0000000000 R11: fffffbfff1f9ecff R12: 0000000000000282
R13: dffffc0000000000 R14: ffffffff8dc4b790 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125a5b000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f337f3e1e9c CR3: 00000000378b6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 trace_irq_disable+0x3b/0x140 include/trace/events/preemptirq.h:36
 __local_bh_enable_ip+0xaa/0x2b0 kernel/softirq.c:270
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 spin_unlock_bh include/linux/spinlock_rt.h:116 [inline]
 __batadv_dat_purge+0x344/0x400 net/batman-adv/distributed-arp-table.c:185
 batadv_dat_purge+0x20/0x70 net/batman-adv/distributed-arp-table.c:204
 process_one_work+0x9a3/0x1710 kernel/workqueue.c:3312
 process_scheduled_works kernel/workqueue.c:3403 [inline]
 worker_thread+0xba8/0x11e0 kernel/workqueue.c:3489
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/24 20:52 linux-next 7080e32d3f09 1c2b9291 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: task hung in process_one_work
2026/01/20 08:26 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 59e4d31a0470 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro #1 (corrupt fs)] [mounted in repro #2 (corrupt fs)] [mounted in repro #3 (clean fs)] ci-upstream-gce-arm64 INFO: task hung in process_one_work
2026/01/19 22:22 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 59e4d31a0470 d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-gce-arm64 INFO: task hung in process_one_work
* Struck through repros no longer work on HEAD.