INFO: task syz.4.514:8729 blocked for more than 143 seconds. Not tainted 6.14.0-rc3-next-20250218-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.514 state:D stack:23968 pid:8729 tgid:8728 ppid:5835 task_flags:0x400140 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5373 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6760 __schedule_loop kernel/sched/core.c:6837 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6852 schedule_timeout+0xb0/0x290 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:225 [inline] __down_common+0x375/0x820 kernel/locking/semaphore.c:246 down+0x84/0xc0 kernel/locking/semaphore.c:63 console_lock+0x145/0x1b0 kernel/printk/printk.c:2833 con_install+0x99/0x7f0 drivers/tty/vt/vt.c:3515 tty_driver_install_tty drivers/tty/tty_io.c:1304 [inline] tty_init_dev+0xc1/0x4c0 drivers/tty/tty_io.c:1416 tty_open_by_driver drivers/tty/tty_io.c:2082 [inline] tty_open+0x9d9/0xde0 drivers/tty/tty_io.c:2129 chrdev_open+0x521/0x600 fs/char_dev.c:414 do_dentry_open+0xdec/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3838 [inline] path_openat+0x2c9f/0x35b0 fs/namei.c:3997 do_filp_open+0x282/0x4e0 fs/namei.c:4024 do_sys_openat2+0x13f/0x1c0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1454 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: 0033:0x7fdde978bad0 RSP: 002b:00007fddea67fb70 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007fdde978bad0 RDX: 0000000000000002 RSI: 00007fddea67fc10 RDI: 00000000ffffff9c RBP: 00007fddea67fc10 R08: 0000000000000000 R09: 00007fddea67f987 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fdde99a5fa0 R15: 00007ffe7668c078 Showing all locks held in the system: 3 locks held by kthreadd/2: 4 locks held by kworker/0:1/9: #0: ffff88801b081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b081d48 ((wq_completion)events_power_efficient){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc900000e7c60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900000e7c60 ((reg_check_chans).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: reg_check_chans_work+0x99/0xfb0 net/wireless/reg.c:2480 #3: ffff888028408768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6061 [inline] #3: ffff888028408768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_leave_invalid_chans net/wireless/reg.c:2468 [inline] #3: ffff888028408768 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: reg_check_chans_work+0x164/0xfb0 net/wireless/reg.c:2483 3 locks held by kworker/u8:0/11: 3 locks held by kworker/u8:1/12: 2 locks held by kworker/1:0/23: 3 locks held by kworker/1:0H/24: #0: ffff888020ee7148 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888020ee7148 ((wq_completion)kblockd){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc900001e7c60 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900001e7c60 ((work_completion)(&q->timeout_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:304 [inline] #2: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:998 1 lock held by khungtaskd/30: #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8eb3b3a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 5 locks held by kworker/u8:2/35: 2 locks held by kworker/1:1/46: 3 locks held by kworker/u8:3/52: 3 locks held by kworker/u8:4/67: 3 locks held by kworker/u8:5/970: 2 locks held by kworker/0:2/975: 6 locks held by kworker/u8:6/1109: 2 locks held by kworker/u8:7/1145: #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b089148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90003c3fc60 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003c3fc60 ((work_completion)(&pool->idle_cull_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 3 locks held by kworker/u8:8/1157: 3 locks held by kworker/u8:9/2997: 3 locks held by kworker/u8:10/3025: 3 locks held by kworker/R-ipv6_/3172: #0: ffff88814d3c6148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814d3c6148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000bf57be0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000bf57be0 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8fee0408 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4730 2 locks held by kworker/R-bat_e/3402: 3 locks held by kworker/u8:11/4173: 2 locks held by jbd2/sda1-8/5168: 2 locks held by syslogd/5188: 3 locks held by klogd/5195: 4 locks held by udevd/5206: 2 locks held by getty/5589: #0: ffff888035b720a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5823: 2 locks held by kworker/0:3/5842: 6 locks held by kworker/u9:3/5844: #0: ffff88802f5c3148 ((wq_completion)hci3){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88802f5c3148 ((wq_completion)hci3){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000420fc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000420fc60 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffff888027e60d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1ec/0x400 net/bluetooth/hci_sync.c:331 #3: ffff888027e60078 (&hdev->lock){+.+.}-{4:4}, at: hci_abort_conn_sync+0x9ee/0x1340 net/bluetooth/hci_sync.c:5569 #4: ffff88801eaf4b38 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x71/0x690 net/bluetooth/l2cap_core.c:1760 #5: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #5: ffffffff8eb408b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x451/0x820 kernel/rcu/tree_exp.h:998 2 locks held by kworker/1:4/5890: 1 lock held by kworker/0:7/5898: 2 locks held by kworker/1:6/5917: 3 locks held by kworker/u8:12/6026: 3 locks held by syz-executor/6863: 6 locks held by syz-executor/7317: 2 locks held by syz-executor/8058: 4 locks held by kworker/u8:13/8695: 2 locks held by syz.3.512/8727: 2 locks held by syz.4.514/8729: #0: ffffffff8f37d1e8 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2046 [inline] #0: ffffffff8f37d1e8 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x232/0xde0 drivers/tty/tty_io.c:2129 #1: ffff88805cd8c1c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x78/0x4c0 drivers/tty/tty_io.c:1415 5 locks held by dhcpcd-run-hook/8775: 2 locks held by kworker/u8:14/8776: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.14.0-rc3-next-20250218-syzkaller #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+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:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 1109 Comm: kworker/u8:6 Not tainted 6.14.0-rc3-next-20250218-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:hlock_class kernel/locking/lockdep.c:230 [inline] RIP: 0010:check_wait_context kernel/locking/lockdep.c:4877 [inline] RIP: 0010:__lock_acquire+0x87f/0x2100 kernel/locking/lockdep.c:5178 Code: 90 48 c1 e8 03 48 89 44 24 70 4d 89 ef 41 83 fc 31 0f 83 1b 02 00 00 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 4c 01 00 00 <41> 8b 5d 00 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 00 RSP: 0018:ffffc90000006090 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ffffffff93ee34fe RCX: 0000000000000003 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff9456b000 RBP: 0000000000000003 R08: ffffffff9456b007 R09: 1ffffffff28ad600 R10: dffffc0000000000 R11: fffffbfff28ad601 R12: 0000000000000005 R13: ffff8880275247d8 R14: 0000000000000005 R15: ffff8880275247d8 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555590b415c8 CR3: 000000003332a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd5/0x2380 arch/x86/kernel/unwind_orc.c:479 __unwind_start+0x59a/0x740 arch/x86/kernel/unwind_orc.c:758 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __set_page_owner+0x89/0x530 mm/page_owner.c:320 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1629 prep_new_page mm/page_alloc.c:1637 [inline] get_page_from_freelist+0x365c/0x37a0 mm/page_alloc.c:3555 __alloc_frozen_pages_noprof+0x292/0x710 mm/page_alloc.c:4817 alloc_pages_mpol+0x311/0x660 mm/mempolicy.c:2301 alloc_slab_page mm/slub.c:2437 [inline] allocate_slab+0x8f/0x3a0 mm/slub.c:2601 new_slab mm/slub.c:2654 [inline] ___slab_alloc+0xc27/0x14a0 mm/slub.c:3840 __slab_alloc+0x58/0xa0 mm/slub.c:3930 __slab_alloc_node mm/slub.c:4005 [inline] slab_alloc_node mm/slub.c:4166 [inline] kmem_cache_alloc_noprof+0x268/0x380 mm/slub.c:4185 skb_ext_maybe_cow net/core/skbuff.c:6942 [inline] skb_ext_add+0x1bd/0x8d0 net/core/skbuff.c:7016 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:169 [inline] br_nf_forward_ip+0xd8/0x7b0 net/bridge/br_netfilter_hooks.c:684 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x2a7/0x460 include/linux/netfilter.h:312 __br_forward+0x489/0x660 net/bridge/br_forward.c:115 br_handle_frame_finish+0x18d2/0x2000 net/bridge/br_input.c:220 br_nf_hook_thresh+0x472/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:282 [inline] br_handle_frame+0x9f3/0x1530 net/bridge/br_input.c:433 __netif_receive_skb_core+0x13e7/0x4540 net/core/dev.c:5723 __netif_receive_skb_one_core net/core/dev.c:5827 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5942 process_backlog+0x662/0x15b0 net/core/dev.c:6294 __napi_poll+0xcb/0x490 net/core/dev.c:7114 napi_poll net/core/dev.c:7183 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7305 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 do_softirq+0x11b/0x1e0 kernel/softirq.c:462 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:389 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x7c4/0xb50 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xabe/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245