INFO: task syz.6.733:9347 blocked for more than 173 seconds. Not tainted 6.12.0-rc6-syzkaller-00110-gff7afaeca1a1 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.6.733 state:D stack:24128 pid:9347 tgid:9347 ppid:6458 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 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 bdev_release+0x17e/0x700 block/bdev.c:1087 blkdev_release+0x15/0x20 block/fops.c:639 __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: 0033:0x7fbedd5b0805 RSP: 002b:00007fbedd85fb20 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 00007fbedd735f80 RCX: 00007fbedd5b0805 RDX: 00007fbedd85fb60 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fbedd737a80 R08: 0000000000000000 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000293 R12: 000000000003abdb R13: 00007fbedd85fc90 R14: 0000000000000032 R15: ffffffffffffffff Showing all locks held in the system: 3 locks held by kworker/u8:0/11: 3 locks held by kworker/u8:1/12: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000117d00 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff888064568768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: wiphy_lock include/net/cfg80211.h:6014 [inline] #2: ffff888064568768 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: cfg80211_wiphy_work+0xd9/0x490 net/wireless/core.c:426 5 locks held by kworker/1:0/25: 1 lock held by khungtaskd/30: #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937da0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 2 locks held by kworker/u8:2/35: 6 locks held by kworker/u9:0/55: 3 locks held by kworker/u8:4/81: 1 lock held by jbd2/sda1-8/5176: 1 lock held by syslogd/5196: 1 lock held by klogd/5203: 1 lock held by udevd/5214: #0: ffff88802553c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_open+0xf0/0xc50 block/bdev.c:904 1 lock held by dhcpcd/5507: 1 lock held by dhcpcd/5508: 2 locks held by getty/5606: #0: ffff8880319a90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/5831: 5 locks held by syz-executor/5861: 2 locks held by syz-executor/5927: 2 locks held by syz.0.77/6272: 3 locks held by kworker/u8:10/6634: 3 locks held by kworker/u8:12/6636: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90003a6fd00 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90003a6fd00 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffff888060aa8768 (&rdev->wiphy.mtx){+.+.}-{3:3} , at: wiphy_lock include/net/cfg80211.h:6014 [inline] , at: cfg80211_wiphy_work+0xd9/0x490 net/wireless/core.c:426 1 lock held by syz.6.733/9347: #0: ffff88802553c4c8 (&disk->open_mutex){+.+.}-{3:3}, at: bdev_release+0x17e/0x700 block/bdev.c:1087 1 lock held by syz.8.738/9381: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc6-syzkaller-00110-gff7afaeca1a1 #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: 25 Comm: kworker/1:0 Not tainted 6.12.0-rc6-syzkaller-00110-gff7afaeca1a1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events dvb_usb_read_remote_control RIP: 0010:__lock_acquire+0x6d/0x2050 kernel/locking/lockdep.c:5065 Code: c0 0f 85 9b 16 00 00 45 31 f6 83 3d a8 ec ac 0e 00 0f 84 b6 13 00 00 89 54 24 54 89 5c 24 68 4c 89 f8 48 c1 e8 03 80 3c 30 00 <74> 12 4c 89 ff e8 a9 51 8e 00 48 be 00 00 00 00 00 fc ff df 49 8b RSP: 0018:ffffc90000a17230 EFLAGS: 00000046 RAX: 1ffffffff34b52df RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffffff9a5a96f8 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001 R10: dffffc0000000000 R11: fffffbfff203a11e R12: ffff88801d2e9e00 R13: 0000000000000001 R14: 0000000000000000 R15: ffffffff9a5a96f8 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000200a0030 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000003 DR1: 0000000000000004 DR2: 0000000100000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:978 [inline] debug_check_no_obj_freed+0x234/0x580 lib/debugobjects.c:1019 slab_free_hook mm/slub.c:2273 [inline] slab_free mm/slub.c:4579 [inline] kmem_cache_free+0x11f/0x420 mm/slub.c:4681 skb_ext_del include/linux/skbuff.h:4843 [inline] nf_bridge_info_free net/bridge/br_netfilter_hooks.c:156 [inline] br_nf_dev_queue_xmit+0x4cb/0x2390 net/bridge/br_netfilter_hooks.c:879 NF_HOOK+0x700/0x7c0 include/linux/netfilter.h:314 br_nf_post_routing+0xa20/0xe80 net/bridge/br_netfilter_hooks.c:994 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_finish+0xd8/0x130 net/bridge/br_forward.c:66 br_nf_forward_finish+0xb49/0xfb0 net/bridge/br_netfilter_hooks.c:690 NF_HOOK+0x700/0x7c0 include/linux/netfilter.h:314 br_nf_forward_ip+0x61e/0x7b0 net/bridge/br_netfilter_hooks.c:744 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+0x18ba/0x1fe0 net/bridge/br_input.c:215 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:277 [inline] br_handle_frame+0x9fd/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x13e8/0x4570 net/core/dev.c:5564 __netif_receive_skb_one_core net/core/dev.c:5668 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5783 process_backlog+0x662/0x15b0 net/core/dev.c:6115 __napi_poll+0xcb/0x490 net/core/dev.c:6779 napi_poll net/core/dev.c:6848 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6970 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 __do_softirq kernel/softirq.c:588 [inline] invoke_softirq kernel/softirq.c:428 [inline] __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_flush_all+0x996/0xeb0 Code: 48 21 c3 0f 85 16 02 00 00 e8 26 7d 20 00 4c 8b 7c 24 10 4d 85 f6 75 07 e8 17 7d 20 00 eb 06 e8 10 7d 20 00 fb 48 8b 5c 24 18 <48> 8b 44 24 30 42 80 3c 28 00 74 08 48 89 df e8 f6 42 8a 00 4c 8b RSP: 0018:ffffc900001f76e0 EFLAGS: 00000293 RAX: ffffffff81745d50 RBX: ffffffff8f182458 RCX: ffff88801d2e9e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900001f7890 R08: ffffffff81745d27 R09: 1ffffffff2859b00 R10: dffffc0000000000 R11: fffffbfff2859b01 R12: ffffffff8f182400 R13: dffffc0000000000 R14: 0000000000000200 R15: ffffc900001f78e0 __console_flush_and_unlock kernel/printk/printk.c:3239 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3279 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2407 _printk+0xd5/0x120 kernel/printk/printk.c:2432 dvb_usb_read_remote_control+0x143/0x1b0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:263 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 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