syzbot


INFO: task hung in em28xx_usb_disconnect (2)

Status: auto-obsoleted due to no activity on 2025/06/09 05:19
Subsystems: media
[Documentation on labels]
First crash: 369d, last: 166d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in em28xx_usb_disconnect media 1 1 1086d 1086d 0/29 auto-obsoleted due to no activity on 2022/12/01 23:16

Sample crash report:
INFO: task kworker/0:11:5923 blocked for more than 143 seconds.
      Not tainted 6.14.0-rc6-syzkaller-00003-g4d872d51bc9d #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/0:11    state:D stack:20720 pid:5923  tgid:5923  ppid:2      task_flags:0x4288060 flags:0x00004000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5378 [inline]
 __schedule+0x190e/0x4c90 kernel/sched/core.c:6765
 __schedule_loop kernel/sched/core.c:6842 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6857
 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common kernel/sched/completion.c:127 [inline]
 wait_for_completion+0x355/0x620 kernel/sched/completion.c:148
 __flush_work+0xa47/0xc60 kernel/workqueue.c:4244
 flush_request_modules drivers/media/usb/em28xx/em28xx-cards.c:3482 [inline]
 em28xx_usb_disconnect+0x190/0x530 drivers/media/usb/em28xx/em28xx-cards.c:4195
 usb_unbind_interface+0x25b/0x940 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1273 [inline]
 device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1296
 bus_remove_device+0x34f/0x420 drivers/base/bus.c:579
 device_del+0x57a/0x9b0 drivers/base/core.c:3855
 usb_disable_device+0x3bf/0x850 drivers/usb/core/message.c:1418
 usb_disconnect+0x340/0x950 drivers/usb/core/hub.c:2316
 hub_port_connect drivers/usb/core/hub.c:5373 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5673 [inline]
 port_event drivers/usb/core/hub.c:5833 [inline]
 hub_event+0x1ebc/0x5150 drivers/usb/core/hub.c:5915
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Showing all locks held in the system:
1 lock held by kthreadd/2:
4 locks held by kworker/R-netns/8:
 #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801bef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc900000d7be0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900000d7be0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8fec94d0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x17a/0xd60 net/core/net_namespace.c:606
 #3: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:415
4 locks held by kworker/0:0/9:
 #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc900000e7c60 ((work_completion)(&dev->request_module_wk)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900000e7c60 ((work_completion)(&dev->request_module_wk)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8fb19068 (em28xx_devlist_mutex){+.+.}-{4:4}, at: em28xx_init_extension+0x32/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1113
 #3: ffff88806f999b88 (&dev->lock#4){+.+.}-{4:4}, at: em28xx_v4l2_init+0xc9/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2530
4 locks held by kworker/0:1/10:
 #0: ffff88801b081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc900000f7c60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900000f7c60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x99/0xfb0 net/wireless/reg.c:2481
 #3: ffff8880553b0768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6061 [inline]
 #3: ffff8880553b0768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2469 [inline]
 #3: ffff8880553b0768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x164/0xfb0 net/wireless/reg.c:2484
3 locks held by kworker/u8:0/12:
3 locks held by kworker/u8:1/13:
3 locks held by kworker/1:0/26:
 #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff88801b080d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc90000a0fc60 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000a0fc60 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
1 lock held by khungtaskd/31:
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746
3 locks held by kworker/u8:3/53:
3 locks held by kworker/u8:4/62:
2 locks held by kswapd0/87:
3 locks held by kworker/u8:5/1097:
3 locks held by kworker/u8:6/2942:
5 locks held by kworker/u8:7/2960:
3 locks held by kworker/u8:8/2981:
3 locks held by kworker/R-ipv6_/3170:
 #0: ffff888030b38148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888030b38148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc9000c7b7be0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc9000c7b7be0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline]
 #2: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4730
2 locks held by kworker/R-bat_e/3400:
3 locks held by kworker/u8:9/3573:
3 locks held by syslogd/5192:
2 locks held by klogd/5199:
2 locks held by udevd/5210:
2 locks held by getty/5588:
 #0: ffff8880314070a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211
1 lock held by syz-executor/5822:
2 locks held by kworker/1:3/5888:
4 locks held by kworker/0:5/5890:
2 locks held by kworker/0:6/5891:
2 locks held by kworker/1:5/5892:
5 locks held by kworker/0:11/5923:
 #0: ffff888021e8a148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888021e8a148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319
 #1: ffffc900043efc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc900043efc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319
 #2: ffff888144ffc190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #2: ffff888144ffc190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5861
 #3: ffff8880642b9190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #3: ffff8880642b9190 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x103/0x950 drivers/usb/core/hub.c:2307
 #4: ffff88805d8a2160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1030 [inline]
 #4: ffff88805d8a2160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline]
 #4: ffff88805d8a2160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293
2 locks held by udevd/7528:
4 locks held by udevd/7529:
 #0: ffff8880332a51c8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb4/0xd70 fs/seq_file.c:182
 #1: ffff88802d943088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x53/0x3b0 fs/kernfs/file.c:154
 #2: ffff88807efc4878 (kn->active#30){.+.+}-{0:0}, at: kernfs_seq_start+0x72/0x3b0 fs/kernfs/file.c:155
 #3: ffff8880642b9190 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1035 [inline]
 #3: ffff8880642b9190 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142
1 lock held by syz-executor/10654:
1 lock held by syz-executor/12964:
4 locks held by dhcpcd-run-hook/14150:
6 locks held by syz.7.1546/14193:
7 locks held by syz.3.1547/14191:
1 lock held by syz.5.1548/14198:
3 locks held by kworker/u8:2/14203:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00003-g4d872d51bc9d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline]
 watchdog+0x1058/0x10a0 kernel/hung_task.c:399
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 2960 Comm: kworker/u8:7 Not tainted 6.14.0-rc6-syzkaller-00003-g4d872d51bc9d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:__this_cpu_preempt_check+0x0/0x20 lib/smp_processor_id.c:65
Code: 1a 1e f5 e8 c2 a2 20 f5 eb a8 e8 ab e0 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 89 fe 48 c7 c7 20 00 81 8c e9 bd fe ff ff 66 2e 0f
RSP: 0018:ffffc90000a28270 EFLAGS: 00000246
RAX: ffff888030508000 RBX: ffff888030508000 RCX: ffffc9000c2b0000
RDX: ffffc90000a28340 RSI: ffffc9000c2b8000 RDI: ffffffff8e4044de
RBP: ffffc90000a282e0 R08: ffffc90000a28300 R09: 0000000000000000
R10: ffffc90000a28340 R11: fffff52000145074 R12: ffffc90000a28340
R13: ffffc90000a28368 R14: ffffc90000a28301 R15: 1ffff9200014506d
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000400000198030 CR3: 000000007c2b4000 CR4: 00000000003526f0
DR0: 0000040000000000 DR1: 000000000000000c DR2: 0000000000000006
DR3: 0000000000000006 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 in_exception_stack arch/x86/kernel/dumpstack_64.c:103 [inline]
 get_stack_info_noinstr+0x47/0x130 arch/x86/kernel/dumpstack_64.c:179
 get_stack_info+0x3c/0xf0 arch/x86/kernel/dumpstack_64.c:199
 __unwind_start+0x434/0x740 arch/x86/kernel/unwind_orc.c:729
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4609 [inline]
 kmem_cache_free+0x195/0x410 mm/slub.c:4711
 kfree_skb_reason include/linux/skbuff.h:1271 [inline]
 kfree_skb include/linux/skbuff.h:1280 [inline]
 ip6_mc_input+0x974/0xb70 net/ipv6/ip6_input.c:591
 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314
 __netif_receive_skb_one_core net/core/dev.c:5893 [inline]
 __netif_receive_skb+0x1ea/0x650 net/core/dev.c:6006
 process_backlog+0x662/0x15b0 net/core/dev.c:6354
 __napi_poll+0xcb/0x490 net/core/dev.c:7188
 napi_poll net/core/dev.c:7257 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7379
 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561
 do_softirq+0x11b/0x1e0 kernel/softirq.c:462
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389
 ieee80211_rx_bss_info net/mac80211/ibss.c:1174 [inline]
 ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1581 [inline]
 ieee80211_ibss_rx_queued_mgmt+0x1b48/0x2e00 net/mac80211/ibss.c:1608
 ieee80211_iface_process_skb net/mac80211/iface.c:1612 [inline]
 ieee80211_iface_work+0x8dc/0xf90 net/mac80211/iface.c:1666
 cfg80211_wiphy_work+0x2f0/0x490 net/wireless/core.c:435
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd30 kernel/workqueue.c:3400
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/03/11 05:16 upstream 4d872d51bc9d 16256247 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_usb_disconnect
2025/01/22 07:56 upstream 62de6e168526 da72ac06 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_usb_disconnect
2024/11/20 23:00 upstream bf9aa14fc523 4fca1650 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: task hung in em28xx_usb_disconnect
2024/08/20 03:05 upstream b0da640826ba 9f0ab3fb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: task hung in em28xx_usb_disconnect
2024/09/19 05:34 upstream 4a39ac5b7d62 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: task hung in em28xx_usb_disconnect
* Struck through repros no longer work on HEAD.