INFO: task syz.7.597:9393 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.7.597 state:D stack:25288 pid:9393 tgid:9390 ppid:7996 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7340 __mutex_lock_common kernel/locking/mutex.c:726 [inline] __mutex_lock+0x7f7/0x1550 kernel/locking/mutex.c:820 device_lock include/linux/device.h:1040 [inline] usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 chrdev_open+0x4cd/0x5e0 fs/char_dev.c:411 do_dentry_open+0x822/0x13a0 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff8ed55d68e RSP: 002b:00007ff8ee48eb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ff8ee48f6c0 RCX: 00007ff8ed55d68e RDX: 0000000000101701 RSI: 00007ff8ee48ec00 RDI: ffffffffffffff9c RBP: 00007ff8ee48ec00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007ff8ed816038 R14: 00007ff8ed815fa0 R15: 00007ff8ed93fa48 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by khugepaged/37: 2 locks held by getty/5384: #0: ffff88803250e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 5 locks held by kworker/1:6/5720: #0: ffff888021ef1540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff888021ef1540 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90004597c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90004597c40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #2: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff88802d4291d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88802d4291d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 #4: ffff8880620011a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #4: ffff8880620011a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x450 drivers/base/dd.c:1076 4 locks held by udevd/5806: #0: ffff888054854758 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff888061e64c80 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888058b3a0f8 (kn->active#29){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888058b3a0f8 (kn->active#29){.+.+}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff88802d4291d8 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:1045 [inline] #3: ffff88802d4291d8 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by syz.7.597/9393: #0: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 1 lock held by syz.0.751/10698: #0: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 1 lock held by syz.7.929/11862: #0: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #0: ffff88802b0a31d8 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 1 lock held by syz.1.950/12023: #0: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.3.952/12042: #0: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.6.955/12061: #0: ffff88807a29a7f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88807a29a7f8 (&mm->mmap_lock){++++}-{4:4}, at: acct_collect+0x19f/0x7c0 kernel/acct.c:568 1 lock held by syz.6.955/12067: #0: ffff88807a29a7f8 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:592 [inline] #0: ffff88807a29a7f8 (&mm->mmap_lock){++++}-{4:4}, at: exit_mm+0x76/0x2d0 kernel/exit.c:557 1 lock held by syz-executor/12070: #0: ffffffff8fdb6be8 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:575 1 lock held by dhcpcd/12078: #0: ffff88806935e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff88806935e260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 1 lock held by dhcpcd/12079: #0: ffff888026578260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1713 [inline] #0: ffff888026578260 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x33/0xe10 net/packet/af_packet.c:3204 3 locks held by dhcpcd-run-hook/12090: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: 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+0x389/0x470 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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12080 Comm: dhcpcd-run-hook Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__list_del_entry_valid_or_report+0xbe/0x190 lib/list_debug.c:71 Code: 1f 0f 85 92 00 00 00 4d 8d 7e 08 4d 89 fc 49 c1 ec 03 43 80 3c 2c 00 74 08 4c 89 ff e8 ab 98 74 fd 49 39 1f 0f 85 9e 00 00 00 01 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc cc 48 c7 c7 a0 ba RSP: 0018:ffffc90005817010 EFLAGS: 00000046 RAX: 1ffffd400028891a RBX: ffffea00014448d0 RCX: 0000000080000001 RDX: ffffea0001f86f50 RSI: ffffffff8e2126b6 RDI: ffffea00014448d8 RBP: ffffc90005817100 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000b02df4 R12: 1ffffd400030e39b R13: dffffc0000000000 R14: ffffea0001871cd0 R15: ffffea0001871cd8 FS: 00007f8b5b69cc80(0000) GS:ffff8881253a9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562367963fd8 CR3: 000000007e76c000 CR4: 00000000003526f0 Call Trace: __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:246 [inline] list_del include/linux/list.h:260 [inline] remove_partial mm/slub.c:3624 [inline] get_partial_node_bulk mm/slub.c:3762 [inline] __refill_objects_node+0x166/0x5c0 mm/slub.c:7124 refill_objects+0x62/0x3d0 mm/slub.c:7259 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x321/0x720 mm/slub.c:4652 alloc_from_pcs mm/slub.c:4750 [inline] slab_alloc_node mm/slub.c:4884 [inline] kmem_cache_alloc_noprof+0x37d/0x650 mm/slub.c:4906 ptlock_alloc+0x20/0x70 mm/memory.c:7579 ptlock_init include/linux/mm.h:3741 [inline] pagetable_pte_ctor include/linux/mm.h:3790 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:79 [inline] pte_alloc_one+0x7a/0x370 arch/x86/mm/pgtable.c:18 __pte_alloc+0x25/0x1a0 mm/memory.c:453 copy_pte_range mm/memory.c:1253 [inline] copy_pmd_range+0x5135/0x5970 mm/memory.c:1408 copy_pud_range mm/memory.c:1445 [inline] copy_p4d_range mm/memory.c:1469 [inline] copy_page_range+0xc13/0x1220 mm/memory.c:1555 dup_mmap+0xf4e/0x1da0 mm/mmap.c:1840 dup_mm kernel/fork.c:1534 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1586 copy_process+0x1f1c/0x4440 kernel/fork.c:2264 kernel_clone+0x2d7/0x940 kernel/fork.c:2722 __do_sys_clone kernel/fork.c:2863 [inline] __se_sys_clone kernel/fork.c:2847 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2847 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8b5b836636 Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffccc391a70 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffccc391a78 RCX: 00007f8b5b836636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000562367953e60 R08: 0000000000000000 R09: 3c00000040001201 R10: 00007f8b5b69cf50 R11: 0000000000000246 R12: 0000562367960710 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000