INFO: task kworker/1:4:5277 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:4 state:D stack:20440 pid:5277 tgid:5277 ppid:2 task_flags:0x4288060 flags:0x00080000 Workqueue: usb_hub_wq hub_event Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x1325/0x47e0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7376 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 __flush_work+0x7c7/0xcb0 kernel/workqueue.c:4448 __cancel_work_sync kernel/workqueue.c:4568 [inline] cancel_delayed_work_sync+0xd1/0xf0 kernel/workqueue.c:4642 __mmc_stop_host drivers/mmc/core/core.c:2368 [inline] __mmc_stop_host drivers/mmc/core/core.c:2357 [inline] mmc_stop_host+0xe9/0x400 drivers/mmc/core/core.c:2373 mmc_remove_host+0x15/0x60 drivers/mmc/core/host.c:681 vub300_disconnect+0x12d/0x170 drivers/mmc/host/vub300.c:2387 usb_unbind_interface+0x1dd/0x9b0 drivers/usb/core/driver.c:460 device_remove drivers/base/dd.c:618 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:610 __device_release_driver drivers/base/dd.c:1349 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1372 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:664 device_del+0x376/0x9b0 drivers/base/core.c:3965 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1484 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2355 hub_port_connect drivers/usb/core/hub.c:5425 [inline] hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] port_event drivers/usb/core/hub.c:5889 [inline] hub_event+0x1d46/0x4510 drivers/usb/core/hub.c:5971 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task kworker/1:6:6002 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:6 state:D stack:21784 pid:6002 tgid:6002 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: events_freezable mmc_rescan Call Trace: context_switch kernel/sched/core.c:5533 [inline] __schedule+0x1325/0x47e0 kernel/sched/core.c:7284 __schedule_loop kernel/sched/core.c:7361 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7376 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x2e7/0x4c0 kernel/sched/completion.c:121 mmc_wait_for_req_done+0xcd/0x3d0 drivers/mmc/core/core.c:408 mmc_wait_for_req+0x207/0x2c0 drivers/mmc/core/core.c:619 mmc_wait_for_cmd+0x154/0x200 drivers/mmc/core/core.c:645 mmc_io_rw_direct_host+0x126/0x330 drivers/mmc/core/sdio_ops.c:83 sdio_reset+0x92/0x240 drivers/mmc/core/sdio_ops.c:209 mmc_rescan_try_freq drivers/mmc/core/core.c:2121 [inline] mmc_rescan+0xba9/0x11c0 drivers/mmc/core/core.c:2316 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396 process_scheduled_works kernel/workqueue.c:3479 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3560 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: locks held by kworker/1:1/29: 6, on CPU#1: #0: ffff888105ec7940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc900001f7d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff88810a70a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88810a70a1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917 #3: ffff88810a70f560 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3270 [inline] #3: ffff88810a70f560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5482 [inline] #3: ffff88810a70f560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #3: ffff88810a70f560 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #3: ffff88810a70f560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2c08/0x4510 drivers/usb/core/hub.c:5971 #4: ffff88810a73c860 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5483 [inline] #4: ffff88810a73c860 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #4: ffff88810a73c860 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #4: ffff88810a73c860 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2c31/0x4510 drivers/usb/core/hub.c:5971 #5: ffffffff8a54a008 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x1a1/0x1d20 drivers/usb/core/hub.c:3085 locks held by khungtaskd/31: 1, last CPU#0: #0: ffffffff898e6f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff898e6f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff898e6f20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6871 locks held by getty/2926: 2, on CPU#1: #0: ffff888114b410a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 locks held by kworker/1:4/5277: 5, on CPU#1: #0: ffff888105ec7940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90003007d18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff88810ab5a1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88810ab5a1d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917 #3: ffff8881174bc1d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #3: ffff8881174bc1d8 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0x10a/0x9a0 drivers/usb/core/hub.c:2346 #4: ffff88811d0891a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #4: ffff88811d0891a0 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1171 [inline] #4: ffff88811d0891a0 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb2/0x620 drivers/base/dd.c:1369 locks held by kworker/0:7/5344: 6, on CPU#0: #0: ffff888105ec7940 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc9000349fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 #2: ffff88810abc21d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88810abc21d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bb/0x4510 drivers/usb/core/hub.c:5917 #3: ffff88810abc7560 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3270 [inline] #3: ffff88810abc7560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5482 [inline] #3: ffff88810abc7560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #3: ffff88810abc7560 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #3: ffff88810abc7560 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x2c08/0x4510 drivers/usb/core/hub.c:5971 #4: ffff88810a727960 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5483 [inline] #4: ffff88810a727960 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5725 [inline] #4: ffff88810a727960 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5889 [inline] #4: ffff88810a727960 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x2c31/0x4510 drivers/usb/core/hub.c:5971 #5: ffffffff8a54a008 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x1a1/0x1d20 drivers/usb/core/hub.c:3085 locks held by kworker/1:6/6002: 2, on CPU#1: #0: ffff88810006a140 ((wq_completion)events_freezable ){+.+.}-{0:0}, at: process_one_work+0x1466/0x1b10 kernel/workqueue.c:3371 #1: ffffc90013907d18 ((work_completion)(&(&host->detect)->work)){+.+.}-{0:0}, at: process_one_work+0xa2c/0x1b10 kernel/workqueue.c:3372 locks held by sed/9510: 2, last CPU#1: #0: ffff888106aa6f40 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:562 [inline] #0: ffff888106aa6f40 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x15e/0x390 mm/util.c:579 #1: ffff8881234cf490 (&anon_vma->rwsem){++++}-{4:4}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #1: ffff8881234cf490 (&anon_vma->rwsem){++++}-{4:4}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffff8881234cf490 (&anon_vma->rwsem){++++}-{4:4}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #1: ffff8881234cf490 (&anon_vma->rwsem){++++}-{4:4}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495 locks held by syz-executor/9511: 1, last CPU#1: #0: ffffffff898e6f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:309 [inline] #0: ffffffff898e6f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff898e6f20 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1216 [inline] #0: ffffffff898e6f20 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x2090 arch/x86/kernel/unwind_orc.c:495 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:123 nmi_trigger_cpumask_backtrace+0x21f/0x2a0 lib/nmi_backtrace.c:66 trigger_all_cpu_backtrace include/linux/nmi.h:164 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x69f/0xc90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2852 Comm: klogd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x4c/0xc0 kernel/rcu/tree.c:753 Code: 00 00 00 48 8d 3c ed e0 ab 46 89 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5d 48 03 1c ed e0 ab 46 89 <48> b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 0f b6 14 02 48 RSP: 0018:ffffc900014e7ae8 EFLAGS: 00000287 RAX: dffffc0000000000 RBX: ffff8881f57339e8 RCX: 0000000000000000 RDX: 1ffffffff128d57d RSI: ffffffff87d2bd00 RDI: ffffffff8946abe8 RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8881150d1100 R13: 0000000000000001 R14: 0000000000000000 R15: ffff8881150d1100 FS: 00007fbf55ab3c80(0000) GS:ffff8882684d7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95de2e74e8 CR3: 0000000117126000 CR4: 00000000003506f0 Call Trace: rcu_read_lock include/linux/rcupdate.h:850 [inline] sk_filter_trim_cap+0x690/0xcd0 net/core/filter.c:161 sk_filter include/linux/filter.h:1179 [inline] unix_dgram_sendmsg+0x5bd/0x1810 net/unix/af_unix.c:2179 sock_sendmsg_nosec net/socket.c:800 [inline] __sock_sendmsg net/socket.c:815 [inline] __sys_sendto+0x48b/0x4e0 net/socket.c:2281 __do_sys_sendto net/socket.c:2288 [inline] __se_sys_sendto net/socket.c:2284 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2284 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x119/0x710 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbf55c03407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff89595ac0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fbf55ab3c80 RCX: 00007fbf55c03407 RDX: 0000000000000058 RSI: 00007fff89595c00 RDI: 0000000000000003 RBP: 00007fff89596030 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007fff89596048 R13: 00007fff89595c00 R14: 000000000000003d R15: 00007fff89595c00