INFO: task syz.3.1306:10434 blocked for more than 143 seconds. Not tainted 6.12.0-rc4-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1306 state:D stack:27360 pid:10434 tgid:10409 ppid:9959 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x18af/0x4bd0 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6839 __mutex_lock_common kernel/locking/mutex.c:684 [inline] __mutex_lock+0x6a7/0xd70 kernel/locking/mutex.c:752 ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f13d7d7dff9 RSP: 002b:00007f13d8b2c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f13d7f36208 RCX: 00007f13d7d7dff9 RDX: 0000000020002eae RSI: 0000000040047451 RDI: 0000000000000006 RBP: 00007f13d7df0296 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f13d7f36208 R15: 00007f13d805fa28 Showing all locks held in the system: 6 locks held by kworker/0:1/9: #0: ffff8880212f1d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8880212f1d48 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff888028d74190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #2: ffff888028d74190 (&dev->mutex){....}-{3:3}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849 #3: ffff888028d77510 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3206 [inline] #3: ffff888028d77510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5418 [inline] #3: ffff888028d77510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #3: ffff888028d77510 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #3: ffff888028d77510 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x25b9/0x5150 drivers/usb/core/hub.c:5903 #4: ffff888028829e68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5419 [inline] #4: ffff888028829e68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] #4: ffff888028829e68 (hcd->address0_mutex){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5821 [inline] #4: ffff888028829e68 (hcd->address0_mutex){+.+.}-{3:3}, at: hub_event+0x25f7/0x5150 drivers/usb/core/hub.c:5903 #5: ffffffff8f5a2010 (ehci_cf_port_reset_rwsem){.+.+}-{3:3}, at: hub_port_reset+0x1f8/0x1b30 drivers/usb/core/hub.c:3021 7 locks held by kworker/u8:1/12: 1 lock held by khungtaskd/30: #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by kworker/u8:9/2588: 2 locks held by getty/4990: #0: ffff88814bb990a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900031332f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 2 locks held by syz.3.1306/10428: 1 lock held by syz.3.1306/10434: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.1.1386/10930: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.1.1386/10932: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.0.1401/11125: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.3.1407/11151: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.3.1407/11152: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.4.1432/11302: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.4.1432/11303: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.2.1513/11847: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.2.1513/11848: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.2.1570/12305: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.2.1570/12307: #0: ffffffff8f4ba848 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x112/0x1cd0 drivers/net/ppp/ppp_generic.c:729 1 lock held by syz.3.1572/12327: #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz.0.1574/12330: #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline] #0: ffffffff8e93d3b8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x451/0x830 kernel/rcu/tree_exp.h:976 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __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:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12330 Comm: syz.0.1574 Not tainted 6.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:stack_trace_consume_entry+0x0/0x280 kernel/stacktrace.c:83 Code: 0c 7e 00 e9 6a ff ff ff e8 3d c6 45 0a 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 fb 48 RSP: 0018:ffffc90004217538 EFLAGS: 00000282 RAX: ffffffff8bc60520 RBX: ffffc90004217540 RCX: ffffffff917bc000 RDX: ffffffff91969701 RSI: ffffffff8bc60520 RDI: ffffc90004217620 RBP: ffffc900042175d0 R08: ffffc90004217f00 R09: 0000000000000000 R10: ffffc90004217590 R11: ffffffff8180a0c0 R12: ffff888045da3c00 R13: ffffffff8180a0c0 R14: ffffc90004217620 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020001403 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000004520 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_stack_walk+0x10e/0x150 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 vfree+0x186/0x2e0 mm/vmalloc.c:3361 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:239 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffa8d37dff9 Code: Unable to access opcode bytes at 0x7ffa8d37dfcf. RSP: 002b:00007ffa8e1810e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007ffa8d536060 RCX: 00007ffa8d37dff9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ffa8d536060 RBP: 00007ffa8d536058 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffa8d536064 R13: 0000000000000000 R14: 00007ffa8d65f940 R15: 00007ffa8d65fa28