INFO: task syz.0.5872:21378 blocked for more than 143 seconds. Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.5872 state:D stack:28216 pid:21378 tgid:21344 ppid:16784 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:867 [inline] vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x274/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_setxattr fs/xattr.c:747 [inline] __se_sys_setxattr fs/xattr.c:743 [inline] __x64_sys_setxattr+0xbc/0xe0 fs/xattr.c:743 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f277098e969 RSP: 002b:00007f27718a0038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007f2770bb6080 RCX: 00007f277098e969 RDX: 0000200000000200 RSI: 00002000000001c0 RDI: 0000200000000000 RBP: 00007f2770a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000841 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f2770bb6080 R15: 00007ffdb1873978 INFO: task syz.0.5872:21380 blocked for more than 144 seconds. Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.5872 state:D stack:28952 pid:21380 tgid:21344 ppid:16784 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176 __down_write_common kernel/locking/rwsem.c:1304 [inline] __down_write kernel/locking/rwsem.c:1313 [inline] down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578 inode_lock include/linux/fs.h:867 [inline] vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x274/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f277098e969 RSP: 002b:00007f277187f038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 00007f2770bb6160 RCX: 00007f277098e969 RDX: 0000200000000340 RSI: 0000200000000180 RDI: 0000200000000040 RBP: 00007f2770a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000000d4 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f2770bb6160 R15: 00007ffdb1873978 Showing all locks held in the system: 4 locks held by kworker/u8:0/12: #0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801aef6148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000117c60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000117c60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2ea710 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x145/0xbd0 net/core/net_namespace.c:608 #3: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: netdev_wait_allrefs_any net/core/dev.c:11176 [inline] #3: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: netdev_run_todo+0x79b/0xea0 net/core/dev.c:11288 1 lock held by khungtaskd/31: #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8df3dce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6764 3 locks held by kworker/u8:3/53: #0: ffff88801a081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 2 locks held by getty/5584: #0: ffff88802ff760a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5826: #0: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3390 3 locks held by kworker/1:12/13920: #0: ffff88801a078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801a078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b1/0x17a0 kernel/workqueue.c:3319 #1: ffffc9000b3e7c60 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000b3e7c60 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ec/0x17a0 kernel/workqueue.c:3319 #2: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #2: ffffffff8df437b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b7/0x730 kernel/rcu/tree_exp.h:998 6 locks held by kworker/0:13/13936: 4 locks held by syz.0.5872/21345: #0: ffff888062376420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88807a768af0 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88807a768af0 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 #2: ffff888062376610 (sb_internal#2){.+.+}-{0:0}, at: xfs_trans_alloc_inode+0x13c/0x4a0 fs/xfs/xfs_trans.c:1096 #3: ffff88807a7688d8 (&xfs_nondir_ilock_class){++++}-{4:4}, at: xfs_trans_alloc_inode+0x161/0x4a0 fs/xfs/xfs_trans.c:1102 2 locks held by syz.0.5872/21378: #0: ffff888062376420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88807a768af0 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88807a768af0 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 2 locks held by syz.0.5872/21380: #0: ffff888062376420 (sb_writers#20){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:556 #1: ffff88807a768af0 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: inode_lock include/linux/fs.h:867 [inline] #1: ffff88807a768af0 (&sb->s_type->i_mutex_key#35){++++}-{4:4}, at: vfs_setxattr+0x144/0x2f0 fs/xattr.c:320 2 locks held by syz-executor/22588: #0: ffff888068124d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff888068124d80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678 #1: ffff888068124078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213 1 lock held by syz-executor/24573: 4 locks held by syz-executor/24604: #0: ffff88806266cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:481 [inline] #0: ffff88806266cd80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x1fe/0x500 net/bluetooth/hci_core.c:2678 #1: ffff88806266c078 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x66a/0x1330 net/bluetooth/hci_sync.c:5213 #2: ffffffff8f45cc88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2065 [inline] #2: ffffffff8f45cc88 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x230 net/bluetooth/hci_conn.c:2534 #3: ffff8880459c7338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x70/0x680 net/bluetooth/l2cap_core.c:1761 1 lock held by syz.5.7116/24622: #0: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3390 1 lock held by syz.9.7117/24624: #0: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:633 [inline] #0: ffffffff8f2f7248 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3390 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:437 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: vkms_vblank_simulate: vblank timer overrun NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3 Comm: pool_workqueue_ Not tainted 6.15.0-rc6-syzkaller-00208-g3c21441eeffc #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x70 kernel/kcov.c:217 Code: 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 90 75 92 65 8b 15 28 9e b5 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 <75> 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 83 fa 02 75 21 RSP: 0018:ffffc90000a08638 EFLAGS: 00000006 RAX: ffffffff818c186f RBX: 0000000000000001 RCX: ffff88801b683c00 RDX: 0000000000010000 RSI: ffffffff8bc1d980 RDI: 0000000000000001 RBP: ffffffff99b50e90 R08: ffff888024448237 R09: 1ffff11004889046 R10: dffffc0000000000 R11: ffffffff8b554840 R12: 1ffffffff336a1d2 R13: 00000000ffffffff R14: dffffc0000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881261c7000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000080 CR3: 000000003aa78000 CR4: 0000000000350ef0 Call Trace: wq_watchdog_touch+0x1f/0x180 kernel/workqueue.c:7622 touch_nmi_watchdog include/linux/nmi.h:147 [inline] wait_for_lsr+0x16a/0x2f0 drivers/tty/serial/8250/8250_port.c:2105 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3348 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3371 [inline] serial8250_console_write+0x134c/0x1ba0 drivers/tty/serial/8250/8250_port.c:3456 console_emit_next_record kernel/printk/printk.c:3138 [inline] console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline] console_unlock+0xc4/0x270 kernel/printk/printk.c:3325 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450 _printk+0xcf/0x120 kernel/printk/printk.c:2475 vkms_vblank_simulate+0x2be/0x320 drivers/gpu/drm/vkms/vkms_crtc.c:27 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lockdep_unregister_key+0x2ba/0x310 kernel/locking/lockdep.c:6613 Code: 00 65 48 8b 05 47 2b d7 10 48 3b 44 24 10 0f 84 30 fe ff ff e8 77 01 b8 09 e8 a2 02 b8 09 41 f7 c7 00 02 00 00 74 be fb 84 db <75> bd eb ce 90 0f 0b 90 31 db eb 89 90 0f 0b 90 e9 36 ff ff ff 48 RSP: 0018:ffffc90000087ca0 EFLAGS: 00000202 RAX: 7efced4f27c68600 RBX: 0000000000000001 RCX: 7efced4f27c68600 RDX: ffffffff93392708 RSI: ffffffff8d75fbf9 RDI: ffffffff8bc1d9a0 RBP: ffff88802b2f9139 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff81ab2c28 R12: 0000000000000000 R13: 0000000000001000 R14: 0000000000000001 R15: 0000000000000212 wq_unregister_lockdep kernel/workqueue.c:4816 [inline] pwq_release_workfn+0x6d5/0x870 kernel/workqueue.c:5112 kthread_worker_fn+0x507/0xb60 kernel/kthread.c:1010 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245