syzbot


INFO: task hung in reap_as

Status: auto-obsoleted due to no activity on 2026/03/28 12:12
Subsystems: usb
[Documentation on labels]
First crash: 139d, last: 139d

Sample crash report:
INFO: task syz.3.3414:20308 blocked for more than 144 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3414      state:D stack:26856 pid:20308 tgid:20307 ppid:19276  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
 device_lock include/linux/device.h:895 [inline]
 reap_as+0x2b3/0x420 drivers/usb/core/devio.c:2097
 proc_reapurb drivers/usb/core/devio.c:2106 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2617 [inline]
 usbdev_ioctl+0x43a/0x4070 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa33418f749
RSP: 002b:00007fa3323ee038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa3343e5fa0 RCX: 00007fa33418f749
RDX: 0000000000000000 RSI: 000000004008550c RDI: 0000000000000006
RBP: 00007fa334213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3343e6038 R14: 00007fa3343e5fa0 R15: 00007fff18c084d8
 </TASK>
INFO: task syz.3.3414:20316 blocked for more than 145 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.3414      state:D stack:29064 pid:20316 tgid:20307 ppid:19276  task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
 device_lock include/linux/device.h:895 [inline]
 usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
 usbdev_ioctl+0x1a8/0x4070 drivers/usb/core/devio.c:2827
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa33418f749
RSP: 002b:00007fa3323cd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa3343e6090 RCX: 00007fa33418f749
RDX: 0000200000000300 RSI: 000000008038550a RDI: 0000000000000006
RBP: 00007fa334213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa3343e6128 R14: 00007fa3343e6090 R15: 00007fff18c084d8
 </TASK>
INFO: task syz.2.3429:20372 blocked for more than 145 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.3429      state:D stack:26856 pid:20372 tgid:20368 ppid:15993  task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1139/0x6150 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:6960
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0xc69/0x1ca0 kernel/locking/mutex.c:776
 device_lock include/linux/device.h:895 [inline]
 usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
 chrdev_open+0x234/0x6a0 fs/char_dev.c:414
 do_dentry_open+0x748/0x1590 fs/open.c:962
 vfs_open+0x82/0x3f0 fs/open.c:1094
 do_open fs/namei.c:4628 [inline]
 path_openat+0x2078/0x3140 fs/namei.c:4787
 do_filp_open+0x20b/0x470 fs/namei.c:4814
 do_sys_openat2+0x121/0x290 fs/open.c:1430
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x174/0x210 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1415d8df90
RSP: 002b:00007f1416bf2b70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1415d8df90
RDX: 0000000000000002 RSI: 00007f1416bf2c10 RDI: 00000000ffffff9c
RBP: 00007f1416bf2c10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: cccccccccccccccd
R13: 00007f1415fe6038 R14: 00007f1415fe5fa0 R15: 00007ffc5efc2958
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8e3c96a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:7/1132:
2 locks held by getty/5575:
 #0: ffff88814e4a20a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x1510 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5800:
6 locks held by kworker/0:2/16807:
 #0: ffff888141aa8d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x128d/0x1b20 kernel/workqueue.c:3232
 #1: ffffc900048afc90 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x914/0x1b20 kernel/workqueue.c:3233
 #2: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #2: ffff888029723198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1c0/0x52f0 drivers/usb/core/hub.c:5899
 #3: ffff8880347a1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #3: ffff8880347a1198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #4: ffff888027aff160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #4: ffff888027aff160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4e0 drivers/base/dd.c:1006
 #5: ffffffff8e27bf30 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xa9/0x250 kernel/umh.c:214
1 lock held by syz.3.3414/20308:
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: reap_as+0x2b3/0x420 drivers/usb/core/devio.c:2097
1 lock held by syz.3.3414/20316:
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: usbdev_do_ioctl drivers/usb/core/devio.c:2611 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: usbdev_ioctl+0x1a8/0x4070 drivers/usb/core/devio.c:2827
4 locks held by udevd/20319:
 #0: ffff8880329b02f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x12d0 fs/seq_file.c:182
 #1: ffff888056361488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172
 #2: ffff888054f115a8 (kn->active#25){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
 #2: ffff888054f115a8 (kn->active#25){.+.+}-{0:0}, at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173
 #3: ffff8880347a1198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline]
 #3: ffff8880347a1198 (&dev->mutex){....}-{4:4}, at: product_show+0x26/0xa0 drivers/usb/core/sysfs.c:141
1 lock held by syz.2.3429/20372:
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
1 lock held by syz.5.3457/20513:
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
1 lock held by syz.7.3447/20601:
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
3 locks held by kworker/u8:34/21263:
 #0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:647 [inline]
 #0: ffff8880b843ac98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:632
 #1: ffff8880b8524608 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline]
 #1: ffff8880b8524608 (psi_seq){-.-.}-{0:0}, at: __schedule+0x19b1/0x6150 kernel/sched/core.c:6857
 #2: ffff88807c0d0788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6363 [inline]
 #2: ffff88807c0d0788 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0x99/0x560 net/wireless/core.c:424
1 lock held by syz.6.3584/21271:
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
1 lock held by syz.9.3609/21429:
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
 #0: ffff888029723198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x1b6/0x8b0 drivers/usb/core/devio.c:1054
4 locks held by syz.2.3713/22095:
 #0: ffff888057f3de08 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1027 [inline]
 #0: ffff888057f3de08 (&sb->s_type->i_mutex_key#12){+.+.}-{4:4}, at: __sock_release+0x86/0x270 net/socket.c:661
 #1: ffffffff901e5e70 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain kernel/notifier.c:379 [inline]
 #1: ffffffff901e5e70 ((netlink_chain).rwsem){++++}-{4:4}, at: blocking_notifier_call_chain+0x53/0xa0 kernel/notifier.c:368
 #2: ffff8880459d04d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nft_rcv_nl_event+0x187/0x6c0 net/netfilter/nf_tables_api.c:12135
 #3: ffffffff8e3d4df8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a3/0x3c0 kernel/rcu/tree_exp.h:343

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 __sys_info lib/sys_info.c:157 [inline]
 sys_info+0x133/0x180 lib/sys_info.c:165
 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline]
 watchdog+0xe66/0x1180 kernel/hung_task.c:515
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14602 Comm: kworker/u8:1 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:mark_held_locks+0x1f/0x80 kernel/locking/lockdep.c:4315
Code: 90 90 90 90 90 90 90 90 90 90 90 8b 87 28 0b 00 00 85 c0 7e 5e 41 55 4c 8d af 30 0b 00 00 41 54 41 89 f4 55 48 89 fd 53 31 db <48> 63 c3 48 8d 04 80 49 8d 74 c5 00 0f b6 46 22 89 c2 83 e2 03 80
RSP: 0018:ffffc9000f197a90 EFLAGS: 00000002
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffff888069c48b30 RDI: ffff888069c48000
RBP: ffff888069c48000 R08: 0000000000000000 R09: 0000000000000001
R10: ffffffff9088b4d7 R11: ffffffff81beef25 R12: 0000000000000002
R13: ffff888069c48b30 R14: ffff888069c48000 R15: 0000000000000080
FS:  0000000000000000(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f45123b7198 CR3: 000000000e184000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4343 [inline]
 lockdep_hardirqs_on_prepare+0xb8/0x1b0 kernel/locking/lockdep.c:4410
 trace_hardirqs_on+0x36/0x40 kernel/trace/trace_preemptirq.c:78
 kcov_remote_stop+0x287/0x590 kernel/kcov.c:1034
 ieee80211_iface_work+0x434/0x1350 net/mac80211/iface.c:1793
 cfg80211_wiphy_work+0x3fb/0x560 net/wireless/core.c:438
 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
 process_scheduled_works kernel/workqueue.c:3340 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/12/28 12:04 upstream d26143bb38e2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: task hung in reap_as
* Struck through repros no longer work on HEAD.