INFO: task syz.0.171:6600 blocked for more than 143 seconds. Not tainted 6.14.0-rc5-syzkaller-00268-g1110ce6a1e34 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.171 state:D stack:27824 pid:6600 tgid:6572 ppid:5828 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0xf43/0x5890 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x6bd/0xb10 kernel/locking/mutex.c:730 blk_trace_startstop+0x80/0x490 kernel/trace/blktrace.c:700 blk_trace_ioctl+0x1b7/0x280 kernel/trace/blktrace.c:742 blkdev_common_ioctl+0x18a4/0x2210 block/ioctl.c:622 blkdev_ioctl+0x1cd/0x6d0 block/ioctl.c:687 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x190/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6fc138d169 RSP: 002b:00007f6fc2104038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f6fc15a6160 RCX: 00007f6fc138d169 RDX: 0000000000000000 RSI: 0000000000001274 RDI: 0000000000000008 RBP: 00007f6fc140e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f6fc15a6160 R15: 00007ffd25c41838 Showing all locks held in the system: 4 locks held by kworker/u8:1/13: 1 lock held by ksoftirqd/0/17: #0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline] #0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:591 1 lock held by rcu_exp_gp_kthr/20: 1 lock held by khungtaskd/31: #0: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x7f/0x390 kernel/locking/lockdep.c:6746 5 locks held by kworker/u8:5/363: #0: ffff88801beeb948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc90002e6fd18 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fee2190 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xca/0xb30 net/core/net_namespace.c:606 #3: ffffffff8fef7ea8 (rtnl_mutex){+.+.}-{4:4}, at: cleanup_net+0x512/0xb30 net/core/net_namespace.c:642 #4: ffffffff8e1c8538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 2 locks held by getty/5586: #0: ffff888037f220a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0xfba/0x1480 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:5/5899: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000317fd18 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffff888078690240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x1bb/0x26d0 drivers/net/netdevsim/fib.c:1490 3 locks held by kworker/u8:10/6394: #0: ffff88803163b148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x1293/0x1ba0 kernel/workqueue.c:3213 #1: ffffc9000c1ffd18 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x921/0x1ba0 kernel/workqueue.c:3214 #2: ffffffff8fef7ea8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #2: ffffffff8fef7ea8 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x121/0x14e0 net/ipv6/addrconf.c:4190 1 lock held by syz.0.171/6602: #0: ffffffff8e1c8538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x1a4/0x3b0 kernel/rcu/tree_exp.h:334 3 locks held by syz-executor/6768: #0: ffff88805c794d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:480 #1: ffff88805c794078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ab/0x11a0 net/bluetooth/hci_sync.c:5185 #2: ffff88805aaf6b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7f/0x730 net/bluetooth/l2cap_core.c:1761 3 locks held by syz-executor/7845: #0: ffff88803349cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:480 #1: ffff88803349c078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ab/0x11a0 net/bluetooth/hci_sync.c:5185 #2: ffff8880295b0338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7f/0x730 net/bluetooth/l2cap_core.c:1761 3 locks held by syz.3.533/8143: #0: ffff8880313fcd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:480 #1: ffff8880313fc078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ab/0x11a0 net/bluetooth/hci_sync.c:5185 #2: ffff888029141338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7f/0x730 net/bluetooth/l2cap_core.c:1761 3 locks held by syz.4.537/8173: #0: ffff88802aad8d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:480 #1: ffff88802aad8078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ab/0x11a0 net/bluetooth/hci_sync.c:5185 #2: ffff888030042b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7f/0x730 net/bluetooth/l2cap_core.c:1761 3 locks held by syz.2.543/8186: #0: ffff88802be7cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close+0x26/0x90 net/bluetooth/hci_core.c:480 #1: ffff88802be7c078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x3ab/0x11a0 net/bluetooth/hci_sync.c:5185 #2: ffff8880304c2338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7f/0x730 net/bluetooth/l2cap_core.c:1761 4 locks held by dhcpcd-run-hook/8231: #0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:606 [inline] #0: ffff8880b863ec18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:591 #1: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #1: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run4+0x1d6/0x5a0 kernel/trace/bpf_trace.c:2414 #2: ffff88801bb6deb8 (&sig->wait_chldexit){....}-{3:3}, at: __wake_up_common_lock kernel/sched/wait.c:105 [inline] #2: ffff88801bb6deb8 (&sig->wait_chldexit){....}-{3:3}, at: __wake_up_sync_key+0x1c/0x50 kernel/sched/wait.c:173 #3: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8e1bd0c0 (rcu_read_lock){....}-{1:3}, at: sig_get_ucounts+0x7f/0x5b0 kernel/signal.c:416 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc5-syzkaller-00268-g1110ce6a1e34 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0xf62/0x12b0 kernel/hung_task.c:399 kthread+0x3af/0x750 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:111