INFO: task syz.3.1762:12832 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1762 state:D stack:24072 pid:12832 tgid:12831 ppid:5843 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 nfsd_nl_version_get_doit+0x16e/0xb60 fs/nfsd/nfsctl.c:1805 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f106b58f749 RSP: 002b:00007f106c42c038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f106b7e5fa0 RCX: 00007f106b58f749 RDX: 0000000000000000 RSI: 00002000000032c0 RDI: 0000000000000003 RBP: 00007f106b613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f106b7e6038 R14: 00007f106b7e5fa0 R15: 00007ffd8ff068d8 INFO: task syz.3.1762:12835 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1762 state:D stack:27352 pid:12835 tgid:12831 ppid:5843 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x149b/0x4fd0 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7017 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:776 nfsd_nl_version_get_doit+0x16e/0xb60 fs/nfsd/nfsctl.c:1805 genl_family_rcv_msg_doit+0x215/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 ____sys_sendmsg+0x505/0x820 net/socket.c:2592 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2646 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2683 [inline] __se_sys_sendmsg net/socket.c:2681 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2681 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f106b58f749 RSP: 002b:00007f106c3ea038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f106b7e6180 RCX: 00007f106b58f749 RDX: 0000000000000000 RSI: 00002000000032c0 RDI: 0000000000000003 RBP: 00007f106b613f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f106b7e6218 R14: 00007f106b7e6180 R15: 00007ffd8ff068d8 Showing all locks held in the system: 1 lock held by rcu_exp_gp_kthr/18: #0: ffff8880b873a918 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 1 lock held by khungtaskd/31: #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df41aa0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5593: #0: ffff8880305c10a0 (&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+0x449/0x1460 drivers/tty/n_tty.c:2211 3 locks held by kworker/1:3/5837: #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline] #0: ffff88813ff15948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340 #1: ffffc900040afbc0 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline] #1: ffffc900040afbc0 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340 #2: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #2: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:956 3 locks held by kworker/1:11/6191: 2 locks held by syz.2.515/8014: #0: ffffffff8f3799f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e237b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_listener_set_doit+0x137/0x1660 fs/nfsd/nfsctl.c:1880 2 locks held by syz.3.1762/12832: #0: ffffffff8f3799f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e237b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x16e/0xb60 fs/nfsd/nfsctl.c:1805 2 locks held by syz.3.1762/12835: #0: ffffffff8f3799f0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218 #1: ffffffff8e237b88 (nfsd_mutex){+.+.}-{4:4}, at: nfsd_nl_version_get_doit+0x16e/0xb60 fs/nfsd/nfsctl.c:1805 5 locks held by syz-executor/12900: #0: ffff88802a0e4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff88802a0e4ec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715 #1: ffff88802a0e40c0 (&hdev->lock){+.+.}-{4:4}, at: hci_dev_close_sync+0x640/0x1100 net/bluetooth/hci_sync.c:5314 #2: ffffffff8f483948 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2143 [inline] #2: ffffffff8f483948 (hci_cb_list_lock){+.+.}-{4:4}, at: hci_conn_hash_flush+0xa1/0x260 net/bluetooth/hci_conn.c:2637 #3: ffff88807b9f4338 (&conn->lock#2){+.+.}-{4:4}, at: l2cap_conn_del+0x7b/0x5b0 net/bluetooth/l2cap_core.c:1763 #4: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #4: ffffffff8df475f8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x36e/0x6e0 kernel/rcu/tree_exp.h:956 1 lock held by syz-executor/13193: #0: ffff88807ad6cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_dev_do_close net/bluetooth/hci_core.c:499 [inline] #0: ffff88807ad6cec0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_unregister_dev+0x212/0x5b0 net/bluetooth/hci_core.c:2715 1 lock held by syz.4.3202/18491: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 18494 Comm: syz.0.3203 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__lock_acquire+0x88b/0x2cf0 kernel/locking/lockdep.c:5233 Code: c1 c5 13 31 d5 01 f3 29 ee 01 eb c1 c5 04 31 f5 48 c1 e5 20 83 3d 48 58 e4 0d 00 4d 89 e5 0f 85 1f 02 00 00 48 83 7c 24 28 00 <0f> 84 b3 01 00 00 41 8b 45 f8 25 ff 1f 00 00 48 0f a3 05 be c9 e9 RSP: 0018:ffffc90000a08980 EFLAGS: 00000002 RAX: 0000000037b0d26d RBX: 00000000cd7164e5 RCX: 00000000fbdfb5db RDX: 000000003a1d9d65 RSI: 000000005bc5bfc0 RDI: ffff88803a84db80 RBP: bcf60b0400000000 R08: ffffffff8175cf68 R09: ffffffff8df41b60 R10: dffffc0000000000 R11: fffffbfff335b7a5 R12: ffff88803a84e750 R13: ffff88803a84e750 R14: ffff88803a84db80 R15: 0000000000000004 FS: 0000000000000000(0000) GS:ffff888125f1f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c371432 CR3: 000000000dd3a000 CR4: 00000000003526f0 Call Trace: lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock_sched include/linux/rcupdate.h:958 [inline] pfn_valid include/linux/mmzone.h:2183 [inline] __virt_addr_valid+0x1e5/0x5c0 arch/x86/mm/physaddr.c:54 kasan_addr_to_slab+0xf/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xf/0xd0 mm/kasan/generic.c:541 insert_work+0x3d/0x330 kernel/workqueue.c:2180 __queue_work+0xcd0/0xf90 kernel/workqueue.c:2335 call_timer_fn+0x16e/0x590 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1794 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x646/0x860 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2404 handle_softirqs+0x22b/0x7c0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x60/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__update_page_owner_free_handle+0xe2/0x470 mm/page_owner.c:284 Code: be 65 03 00 00 48 c7 c2 40 1e 79 8b e8 27 4f 6d ff 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 30 65 9a 8d 48 c1 e8 03 80 3c 18 00 <74> 0c 48 c7 c7 30 65 9a 8d e8 d0 2e f6 ff 4c 2b 25 09 7c 69 0b 49 RSP: 0018:ffffc90004f47828 EFLAGS: 00000246 RAX: 1ffffffff1b34ca6 RBX: dffffc0000000000 RCX: ffff88803a84db80 RDX: 0000000000000000 RSI: ffffffff8bc083c0 RDI: ffffffff8bc08380 RBP: 0000000000000000 R08: ffffffff8230e85e R09: ffffffff8df41aa0 R10: 000000000000000c R11: ffffffff81acf3d0 R12: ffffea00027b8240 R13: 0000000000000000 R14: ffffffff8230e85e R15: 0000005d7e4baca7 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:321 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xbc8/0xd30 mm/page_alloc.c:2943 vfree+0x25a/0x400 mm/vmalloc.c:3466 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x44c/0xa70 fs/file_table.c:468 task_work_run+0x1d4/0x260 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x694/0x22f0 kernel/exit.c:971 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4e0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2b7/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b95b8f749 Code: Unable to access opcode bytes at 0x7f5b95b8f71f. RSP: 002b:00007f5b96952038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: 000000000000000c RBX: 00007f5b95de6090 RCX: 00007f5b95b8f749 RDX: 0000000000000040 RSI: 0000200000000240 RDI: 000000000000001c RBP: 00007f5b95c13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5b95de6128 R14: 00007f5b95de6090 R15: 00007ffc552dce08