INFO: task syz.5.1417:12610 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1417 state:D stack:28904 pid:12610 tgid:12579 ppid:7306 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5254 [inline] __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862 __schedule_loop kernel/sched/core.c:6944 [inline] schedule+0x165/0x360 kernel/sched/core.c:6959 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 fdget_pos+0x247/0x320 fs/file.c:1232 class_fd_pos_constructor include/linux/file.h:85 [inline] ksys_write+0x79/0x250 fs/read_write.c:729 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7015d8efc9 RSP: 002b:00007f7016bd2038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f7015fe6180 RCX: 00007f7015d8efc9 RDX: 0000000000000118 RSI: 0000200000000400 RDI: 0000000000000008 RBP: 00007f7015e11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7015fe6218 R14: 00007f7015fe6180 R15: 00007ffe69d30358 Showing all locks held in the system: 2 locks held by ksoftirqd/0/15: #0: ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 #1: ffff8880b8624048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 1 lock held by khungtaskd/31: #0: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5589: #0: ffff88814e4360a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900036bb2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by kworker/0:3/5892: #0: ffff88801faf3148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801faf3148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc900044dfba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc900044dfba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888027cfa198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #2: ffff888027cfa198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4b50 drivers/usb/core/hub.c:5899 #3: ffff888026ba1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #3: ffff888026ba1198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #4: ffff888027628160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline] #4: ffff888027628160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 4 locks held by udevd/6084: #0: ffff88805b1fa8b8 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe20 fs/seq_file.c:182 #1: ffff888068d75488 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888053bca4b8 (kn->active#31){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888053bca4b8 (kn->active#31){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff888026ba1198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:919 [inline] #3: ffff888026ba1198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 4 locks held by kworker/u8:17/6112: #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813fe29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000ade7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000ade7ba0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffffffff8f2d4888 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 #3: ffffffff8df43038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #3: ffffffff8df43038 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:957 3 locks held by syz.5.1417/12580: 1 lock held by syz.5.1417/12610: #0: ffff88803349b978 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x247/0x320 fs/file.c:1232 2 locks held by syz-executor/14322: #0: ffffffff8f7f6a90 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8f7f6a90 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8f7f6a90 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f2d4888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f2d4888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f2d4888 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064 2 locks held by dhcpcd-run-hook/14542: #0: ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646 #1: ffff8880b8724048 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: 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:337 [inline] watchdog+0xfa9/0xff0 kernel/hung_task.c:500 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 13561 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0033:0x7f1671bb6df9 Code: 1d 13 00 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 e7 02 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 <8b> 90 08 03 00 00 48 8d b8 08 03 00 00 89 d1 89 d0 83 e1 fd f0 0f RSP: 002b:00007ffdfadcf848 EFLAGS: 00000246 RAX: 000055558de13500 RBX: 000000000000006c RCX: 00007f1671bc1885 RDX: 00007ffdfadcf890 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdfadcf8fc R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000001388 R13: 00000000000927c0 R14: 00000000000b9538 R15: 00007ffdfadcf950 FS: 000055558de13500 GS: 0000000000000000