INFO: task dhcpcd:5434 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:dhcpcd state:D stack:24688 pid:5434 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 netlink_dump+0x71f/0xde0 net/netlink/af_netlink.c:2263 __netlink_dump_start+0x5f1/0x810 net/netlink/af_netlink.c:2372 netlink_dump_start include/linux/netlink.h:338 [inline] rtnetlink_rcv_msg+0xba1/0xf10 net/core/rtnetlink.c:6428 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x5bf/0x950 net/socket.c:2595 ___sys_sendmsg+0x220/0x290 net/socket.c:2649 __sys_sendmsg net/socket.c:2678 [inline] __do_sys_sendmsg net/socket.c:2687 [inline] __se_sys_sendmsg+0x1a5/0x270 net/socket.c:2685 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f13d9da2407 RSP: 002b:00007fff5b343190 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f13d9d18740 RCX: 00007f13d9da2407 RDX: 0000000000000000 RSI: 00007fff5b343210 RDI: 000000000000000c RBP: 00007fff5b347430 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005623c9780c60 R13: 000000000000000c R14: 00007fff5b3473f0 R15: 00007fff5b347430 INFO: task syz-executor:6835 blocked for more than 146 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22280 pid:6835 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 rtnl_lock net/core/rtnetlink.c:78 [inline] rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f203d9915dc RSP: 002b:00007ffde1fcccc0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f203e714620 RCX: 00007f203d9915dc RDX: 0000000000000054 RSI: 00007f203e714670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffde1fccd14 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f203e714670 R15: 0000000000000000 INFO: task syz-executor:6894 blocked for more than 147 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:23496 pid:6894 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 rtnl_lock net/core/rtnetlink.c:78 [inline] rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 netlink_rcv_skb+0x216/0x480 net/netlink/af_netlink.c:2545 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x751/0x8d0 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c1/0xbe0 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] __sys_sendto+0x46a/0x620 net/socket.c:2201 __do_sys_sendto net/socket.c:2213 [inline] __se_sys_sendto net/socket.c:2209 [inline] __x64_sys_sendto+0xde/0xf0 net/socket.c:2209 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fb66f1915dc RSP: 002b:00007ffdbf1a17f0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fb66ff14620 RCX: 00007fb66f1915dc RDX: 000000000000002c RSI: 00007fb66ff14670 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00007ffdbf1a1844 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fb66ff14670 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u4:0/11: #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871538 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000107d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:286 3 locks held by kworker/1:1/27: #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000a2fd00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000a2fd00 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 3 locks held by kworker/u4:2/42: #0: ffff88802c1bf538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff88802c1bf538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90000b2fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90000b2fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x14e0 net/ipv6/addrconf.c:4158 3 locks held by kworker/0:2/967: 3 locks held by kworker/u4:10/1339: 2 locks held by dhcpcd/5434: #0: ffff888019a84690 (nlk_cb_mutex-ROUTE){+.+.}-{3:3}, at: __netlink_dump_start+0xf4/0x810 net/netlink/af_netlink.c:2336 #1: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: netlink_dump+0x71f/0xde0 net/netlink/af_netlink.c:2263 2 locks held by getty/5532: #0: ffff88814ce250a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 3 locks held by kworker/0:5/6162: 2 locks held by syz.1.282/6784: 1 lock held by syz.2.305/6834: 1 lock held by syz-executor/6835: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/6894: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/6916: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 1 lock held by syz.0.326/6920: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_detach drivers/net/tun.c:698 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: tun_chr_close+0x41/0x1c0 drivers/net/tun.c:3511 1 lock held by syz-executor/6931: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/6936: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/6938: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/6941: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/6964: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/6977: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/7005: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 1 lock held by syz-executor/7012: #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:78 [inline] #0: ffffffff8dfb5448 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x76f/0xf10 net/core/rtnetlink.c:6469 2 locks held by kworker/1:2/7023: #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900032e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900032e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 5 locks held by syz-executor/7032: #0: ffff8880222f4e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline] #0: ffff8880222f4e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x510 net/bluetooth/hci_core.c:2709 #1: ffff8880222f40b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x4c9/0xfb0 net/bluetooth/hci_sync.c:5273 #2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2011 [inline] #2: ffffffff8e1225c8 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0xa1/0x220 net/bluetooth/hci_conn.c:2540 #3: ffff8880463d1338 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x70/0x660 net/bluetooth/l2cap_core.c:1763 #4: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #4: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x448/0x830 kernel/rcu/tree_exp.h:1004 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6784 Comm: syz.1.282 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:multiq3_attach+0x686/0x940 drivers/comedi/drivers/multiq3.c:315 Code: 00 74 08 48 89 df e8 b9 a7 db f9 8b 13 83 c2 0e b0 38 ee 41 80 3c 2c 00 74 08 48 89 df e8 a2 a7 db f9 8b 13 83 c2 0e b0 02 ee <41> 0f b6 04 2e 84 c0 75 25 48 8b 04 24 44 3b 38 7d 35 e8 93 39 84 RSP: 0018:ffffc90003697ab8 EFLAGS: 00000202 RAX: 0000000000000002 RBX: ffff88802b8559d0 RCX: 0000000000080000 RDX: 000000000000200e RSI: 000000000007ffff RDI: 0000000000080000 RBP: dffffc0000000000 R08: 0000000000000040 R09: 1ffffffff21b28b0 R10: dffffc0000000000 R11: fffffbfff21b28b1 R12: 1ffff1100570ab3a R13: 00000000017eef40 R14: 1ffff11005d80a92 R15: 00000000002fdde9 FS: 00007f06d9f7e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd0d641f38 CR3: 000000004fb1a000 CR4: 00000000003506f0 Call Trace: comedi_device_attach+0x518/0x710 drivers/comedi/drivers.c:1006 do_devconfig_ioctl drivers/comedi/comedi_fops.c:872 [inline] comedi_unlocked_ioctl+0x606/0xfe0 drivers/comedi/comedi_fops.c:2178 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f06d918f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f06d9f7e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f06d93e6180 RCX: 00007f06d918f749 RDX: 00002000000000c0 RSI: 0000000040946400 RDI: 0000000000000005 RBP: 00007f06d9213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f06d93e6218 R14: 00007f06d93e6180 R15: 00007fff2aeba1a8