INFO: task syz.5.4470:20321 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.5.4470 state:D stack:27312 pid:20321 tgid:20319 ppid:15896 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1709/0x5530 kernel/sched/core.c:7231 __schedule_loop kernel/sched/core.c:7308 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7323 cgroup_lock_and_drain_offline+0x51a/0x650 kernel/cgroup/cgroup.c:3275 cgroup_kn_lock_live+0x120/0x230 kernel/cgroup/cgroup.c:1715 cgroup_subtree_control_write+0x4b5/0x1080 kernel/cgroup/cgroup.c:3577 cgroup_file_write+0x331/0x8f0 kernel/cgroup/cgroup.c:4316 kernfs_fop_write_iter+0x3a5/0x540 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x17b/0x530 arch/x86/entry/syscall_64.c:85 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f062446de99 RSP: 002b:00007f06226a5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f06246f6090 RCX: 00007f062446de99 RDX: 0000000000000004 RSI: 0000200000000080 RDI: 000000000000000b RBP: 00007f0624503eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f06246f6128 R14: 00007f06246f6090 R15: 00007ffe16d4bc38 Showing all locks held in the system: locks held by khungtaskd/40: 1, last CPU#0: #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6835 locks held by kworker/u8:7/157: 5, last CPU#1: #0: ffff888060a5d138 ((wq_completion)wg-kex-wg1#20){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff888060a5d138 ((wq_completion)wg-kex-wg1#20){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff888060a5d138 ((wq_completion)wg-kex-wg1#20){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc9000411fc60 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc9000411fc60 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc9000411fc60 ((work_completion)(&peer->transmit_handshake_work)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffff88805a3397b8 (&wg->static_identity.lock){++++}-{4:4}, at: wg_noise_handshake_create_initiation+0x12e/0x810 drivers/net/wireguard/noise.c:529 #3: ffff88805b61ee88 (&handshake->lock){++++}-{4:4}, at: rwbase_write_lock+0x17d/0x720 kernel/locking/rwbase_rt.c:259 #4: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: read_lock_bh include/linux/rwlock_rt.h:45 [inline] #4: ffffffff8e3c3880 (rcu_read_lock){....}-{1:3}, at: wg_socket_send_skb_to_peer+0x6e/0x200 drivers/net/wireguard/socket.c:172 locks held by getty/5348: 2, on CPU#0: #0: ffff88803713b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900044c32e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 locks held by kworker/0:3/5582: 6, on CPU#0: #0: ffff88801af8ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffff88801af8ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffff88801af8ed38 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #1: ffffc90004c8fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #1: ffffc90004c8fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #1: ffffc90004c8fc60 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7fd/0x1480 kernel/workqueue.c:3344 #2: ffff88802b34e210 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1104 [inline] #2: ffff88802b34e210 (&dev->mutex){....}-{4:4}, at: hub_event+0x187/0x4cf0 drivers/usb/core/hub.c:5899 #3: ffff88802b373658 (&port_dev->status_lock){+.+.}-{4:4}, at: usb_lock_port drivers/usb/core/hub.c:3252 [inline] #3: ffff88802b373658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5464 [inline] #3: ffff88802b373658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #3: ffff88802b373658 (&port_dev->status_lock){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #3: ffff88802b373658 (&port_dev->status_lock){+.+.}-{4:4}, at: hub_event+0x20ad/0x4cf0 drivers/usb/core/hub.c:5953 #4: ffff88802a4bb158 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect drivers/usb/core/hub.c:5465 [inline] #4: ffff88802a4bb158 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] #4: ffff88802a4bb158 (hcd->address0_mutex){+.+.}-{4:4}, at: port_event drivers/usb/core/hub.c:5871 [inline] #4: ffff88802a4bb158 (hcd->address0_mutex){+.+.}-{4:4}, at: hub_event+0x20e1/0x4cf0 drivers/usb/core/hub.c:5953 #5: ffffffff8f06a920 (ehci_cf_port_reset_rwsem){.+.+}-{4:4}, at: hub_port_reset+0x14d/0x1800 drivers/usb/core/hub.c:3067 locks held by syz.5.4470/20321: 3, on CPU#1: #0: ffff88803196e928 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x252/0x320 fs/file.c:1259 #1: ffff888026bba510 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2731 [inline] #1: ffff888026bba510 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x231/0xbb0 fs/read_write.c:683 #2: ffff88801b76e478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1d9/0x540 fs/kernfs/file.c:336 locks held by syz.1.5097/22531: 1, last CPU#1: #0: ffff88803f27e448 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 40 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 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+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 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: 22531 Comm: syz.1.5097 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:write_comp_data kernel/kcov.c:241 [inline] RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0xa0 kernel/kcov.c:296 Code: 89 44 0a 20 c3 cc cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d f8 38 fd 10 65 44 8b 05 18 39 fd 10 41 81 e0 00 00 ff RSP: 0000:ffffc90004b8f958 EFLAGS: 00000246 RAX: ffffffff8b48a872 RBX: 0000000000000001 RCX: ffff8880324d0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880372ac800 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000100 R11: 0000000000000004 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000200001000000 R15: 0000000000000000 FS: 000055556a42f500(0000) GS:ffff888125af2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000100 CR3: 00000000641b8000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: mas_prev_slot+0x2a2/0xc00 lib/maple_tree.c:4059 vma_prev include/linux/mm.h:1667 [inline] find_mergeable_anon_vma+0x44f/0x860 mm/vma.c:2099 __anon_vma_prepare+0xd7/0x4d0 mm/rmap.c:198 __vmf_anon_prepare mm/memory.c:3906 [inline] vmf_anon_prepare mm/internal.h:568 [inline] do_anonymous_page mm/memory.c:5423 [inline] do_pte_missing+0x1d2a/0x28f0 mm/memory.c:4643 handle_pte_fault mm/memory.c:6503 [inline] __handle_mm_fault mm/memory.c:6652 [inline] handle_mm_fault+0xf95/0x28d0 mm/memory.c:6821 do_user_addr_fault+0xa4d/0x1340 arch/x86/mm/fault.c:1343 handle_page_fault arch/x86/mm/fault.c:1483 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1536 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595 RIP: 0033:0x7fa18c40cd58 Code: fc 89 37 c3 c5 fa 6f 06 c5 fa 6f 4c 16 f0 c5 fa 7f 07 c5 fa 7f 4c 17 f0 c3 66 0f 1f 84 00 00 00 00 00 48 8b 4c 16 f8 48 8b 36 <48> 89 37 48 89 4c 17 f8 c3 c5 fe 6f 54 16 e0 c5 fe 6f 5c 16 c0 c5 RSP: 002b:00007fff18d251c8 EFLAGS: 00010206 RAX: 0000200000000100 RBX: 0000000000000004 RCX: 007165732f646e73 RDX: 000000000000000d RSI: 646e732f7665642f RDI: 0000200000000100 RBP: fffffffffffffffe R08: 0000001b2d920000 R09: 0000000000000001 R10: 7ffffffffffffff2 R11: 0000000000000009 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000133fbe R15: 00007fff18d25460