INFO: task syz.1.3192:24123 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.3192 state:D stack:28160 pid:24123 tgid:24122 ppid:10932 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0x164/0x360 kernel/sched/core.c:7005 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 ___down_common kernel/locking/semaphore.c:268 [inline] __down_common+0x321/0x730 kernel/locking/semaphore.c:293 down+0x80/0xd0 kernel/locking/semaphore.c:100 console_lock+0x58/0x90 kernel/printk/printk.c:2896 do_fb_ioctl+0x5f1/0x800 drivers/video/fbdev/core/fb_chrdev.c:86 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb2299c799 RSP: 002b:00007feb237b4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007feb22c15fa0 RCX: 00007feb2299c799 RDX: 0000200000000040 RSI: 0000000000004601 RDI: 0000000000000004 RBP: 00007feb22a32c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb22c16038 R14: 00007feb22c15fa0 R15: 00007ffea74de2e8 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:6/148: #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88813fe4c148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc90002e57c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90002e57c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8fbcd688 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/u8:8/1106: 2 locks held by getty/5577: #0: ffff888036fea0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:13/6696: #0: ffff88801b6d6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff88801b6d6948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc9000d63fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc9000d63fc40 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8fbbeef0 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf4/0x800 net/core/net_namespace.c:675 #3: ffffffff8fbcd688 (rtnl_mutex){+.+.}-{4:4}, at: caif_exit_net+0x6a/0x4a0 net/caif/caif_dev.c:528 4 locks held by kworker/u8:5/9921: 4 locks held by kworker/u8:0/18566: 3 locks held by kworker/u9:2/20390: #0: ffff8880778fc948 ((wq_completion)hci8){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline] #0: ffff8880778fc948 ((wq_completion)hci8){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358 #1: ffffc900055a7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc900055a7c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffff88803fa58ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331 6 locks held by syz.0.3182/24094: 2 locks held by syz.3.3261/24586: #0: ffffffff8eff3828 (tty_mutex){+.+.}-{4:4}, at: tty_open_by_driver drivers/tty/tty_io.c:2037 [inline] #0: ffffffff8eff3828 (tty_mutex){+.+.}-{4:4}, at: tty_open+0x22d/0xd70 drivers/tty/tty_io.c:2120 #1: ffff88807d0c61c0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0 drivers/tty/tty_io.c:1406 8 locks held by syz-executor/25204: #0: ffff888033146420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline] #0: ffff888033146420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684 #1: ffff88802a155c88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1de/0x540 fs/kernfs/file.c:343 #2: ffff88802804a788 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88802804a788 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x231/0x540 fs/kernfs/file.c:344 #3: ffffffff8f441f48 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd7/0x370 drivers/net/netdevsim/bus.c:234 #4: ffff88807c6a10e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff88807c6a10e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline] #4: ffff88807c6a10e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304 #5: ffff88807c6a4250 (&devlink->lock_key#22){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x170 drivers/net/netdevsim/dev.c:1778 #6: ffffffff8fbcd688 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1177 #7: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #7: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by syz.4.3481/25591: 1 lock held by syz.4.3481/25600: 1 lock held by syz.5.3485/25592: #0: ffff888022395900 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline] #0: ffff888022395900 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x234/0x4f0 mm/util.c:579 1 lock held by syz.5.3485/25593: 2 locks held by syz.0.3487/25596: 2 locks held by syz.6.3486/25598: 2 locks held by syz.8.3488/25601: #0: ffff88807b78f508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff88807b78f508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:661 [inline] #0: ffff88807b78f508 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1455 #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x38d/0x770 kernel/rcu/tree_exp.h:961 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 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: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: be 6c 02 e9 8e 12 62 f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 32 1b 00 fb f4 67 12 62 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffc90000197e20 EFLAGS: 00000246 RAX: 00000000044983dd RBX: ffffffff819a8c8a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8def61cd RDI: ffffffff8c27bc00 RBP: ffffc90000197f10 R08: ffff8880b873395b R09: 1ffff110170e672b R10: dffffc0000000000 R11: ffffed10170e672c R12: ffffffff901196b0 R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff11003a5f000 FS: 0000000000000000(0000) GS:ffff888125560000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000052eff000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ba/0x5d0 kernel/sched/idle.c:341 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:439 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147