INFO: task udevd:17074 blocked for more than 143 seconds. Not tainted syzkaller #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23520 pid:17074 tgid:17074 ppid:5195 task_flags:0x40054c flags:0x00080003 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 io_schedule+0x7f/0xd0 kernel/sched/core.c:7832 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323 __folio_lock mm/filemap.c:1704 [inline] folio_lock include/linux/pagemap.h:1170 [inline] __filemap_get_folio_mpol+0x13e/0xb00 mm/filemap.c:1959 __filemap_get_folio include/linux/pagemap.h:774 [inline] truncate_inode_pages_range+0x48b/0xe30 mm/truncate.c:413 kill_bdev block/bdev.c:91 [inline] blkdev_flush_mapping+0x109/0x2f0 block/bdev.c:728 blkdev_put_whole block/bdev.c:735 [inline] bdev_release+0x417/0x650 block/bdev.c:1160 blkdev_release+0x15/0x20 block/fops.c:705 __fput+0x44f/0xa70 fs/file_table.c:469 task_work_run+0x1d9/0x270 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x70f/0x23c0 kernel/exit.c:976 do_group_exit+0x21b/0x2d0 kernel/exit.c:1118 get_signal+0x1284/0x1330 kernel/signal.c:3034 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __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 include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3c12ca7407 RSP: 002b:00007ffc7985b790 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: fffffffffffffffc RBX: 00007f3c133a5880 RCX: 00007f3c12ca7407 RDX: 0000000000000200 RSI: 00007f3c133a4000 RDI: 0000000000000009 RBP: 000055e2303c0050 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 000055e2303c1e98 R15: 00007f3c134cc39c Showing all locks held in the system: 1 lock held by khungtaskd/30: #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/u8:3/49: #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: ffffc90000b97c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #1: ffffc90000b97c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358 #2: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 5 locks held by kworker/u8:10/3480: #0: ffff8880b873ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b8726118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x8ee/0xf30 kernel/time/timer.c:1117 #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1193 [inline] #3: ffffffff8e75e420 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xa5/0x23c0 arch/x86/kernel/unwind_orc.c:495 #4: ffffffff8e602de8 (text_mutex){+.+.}-{4:4}, at: fs_reclaim_acquire+0x7c/0x100 mm/page_alloc.c:4365 1 lock held by dhcpcd/5490: #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_deladdr+0x1c1/0x790 net/ipv4/devinet.c:670 2 locks held by getty/5586: #0: ffff8880369ab0a0 (&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 1 lock held by udevd/17074: #0: ffff8880269d8358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_release+0x1a9/0x650 block/bdev.c:1144 6 locks held by syz.0.6713/32206: #0: ffffffff8fbb85d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8f91f010 (devices_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x200/0x2f0 drivers/infiniband/core/device.c:1187 #2: ffffffff8f91f1d0 (rdma_nets_rwsem){++++}-{4:4}, at: rdma_dev_init_net+0x238/0x2f0 drivers/infiniband/core/device.c:1192 #3: ffff888035a3cfb0 (&device->compat_devs_mutex){+.+.}-{4:4}, at: add_one_compat_dev+0xf0/0x650 drivers/infiniband/core/device.c:951 #4: ffff888035a3d2a8 (&rxe->usdev_lock){+.+.}-{4:4}, at: rxe_query_port+0x7e/0x3d0 drivers/infiniband/sw/rxe/rxe_verbs.c:61 #5: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: ib_get_eth_speed+0x173/0x7f0 drivers/infiniband/core/verbs.c:2053 2 locks held by syz.0.6713/32211: #0: ffffffff8fbb85d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2d7/0x840 net/ipv4/ip_tunnel.c:1146 2 locks held by syz.4.6718/32227: #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:634 [inline] #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3436 #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8e7646b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz.1.6719/32238: #0: ffffffff9011a8d0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff9011a8d0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff9011a8d0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071 2 locks held by syz.1.6719/32245: #0: ffffffff8fbb85d0 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x4f7/0x730 net/core/net_namespace.c:577 #1: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #1: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: register_netdevice_notifier_net+0x1a/0xa0 net/core/dev.c:2103 1 lock held by syz.2.6720/32236: #0: ffff888055e5fac8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #0: ffff888055e5fac8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: __sock_release net/socket.c:655 [inline] #0: ffff888055e5fac8 (&sb->s_type->i_mutex_key#14){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1448 1 lock held by syz.2.6720/32241: #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: devinet_ioctl+0x32b/0x1b30 net/ipv4/devinet.c:1120 1 lock held by syz.2.6720/32246: #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: __tun_chr_ioctl+0x3bc/0x1e10 drivers/net/tun.c:3078 2 locks held by syz.2.6720/32248: #0: ffff8880326854d8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x3b/0x100 net/netfilter/nf_tables_api.c:11349 #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 1 lock held by syz.2.6720/32251: #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8fbc6d48 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_delroute+0x130/0x330 net/ipv4/fib_frontend.c:888 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 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: 3480 Comm: kworker/u8:10 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 Workqueue: krds_cp_wq#8/0 rds_connect_worker RIP: 0010:unwind_next_frame+0xe9f/0x23c0 arch/x86/kernel/unwind_orc.c:607 Code: b9 00 49 89 1f 48 8b 44 24 58 80 3c 28 00 48 8b 5c 24 78 4c 8b 64 24 48 74 08 48 89 df e8 89 4d b9 00 48 8b 44 24 18 48 89 03 10 00 00 00 4c 89 e7 31 f6 e8 52 4f b9 00 48 8b 14 24 e9 ca 04 RSP: 0018:ffffc90000a08778 EFLAGS: 00000046 RAX: ffffc9000dd0f790 RBX: ffffc90000a08880 RCX: 1ffff92000141101 RDX: ffffffff91355714 RSI: 0000000000000002 RDI: ffffc9000dd0f788 RBP: dffffc0000000000 R08: 0000000000000001 R09: ffffffff8e75e420 R10: ffffc90000a08898 R11: ffffffff81b0bfa0 R12: ffffc90000a08898 R13: 1ffff9200014110b R14: ffffc90000a08848 R15: ffffc90000a08890 FS: 0000000000000000(0000) GS:ffff888125564000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3fc0d00286 CR3: 000000007e61c000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 insert_work+0x3d/0x330 kernel/workqueue.c:2199 __queue_work+0xd03/0x1020 kernel/workqueue.c:2354 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1794 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x67e/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x870 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x5f/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:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:5945 Code: 18 00 00 b8 ff ff ff ff 65 0f c1 05 04 10 6d 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 cb e2 02 00 cc 90 0f 0b 90 48 c7 RSP: 0018:ffffc9000dd0f4c8 EFLAGS: 00000206 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8e16afdc RDI: ffffffff8c27b500 RBP: 00000000ffffffff R08: ffffc9000dd0f6ef R09: 0000000000000000 R10: ffffc9000dd0f6c0 R11: fffff52001ba1ede R12: 0000000000000246 R13: ffff888032f30000 R14: ffffffff8fbc6d48 R15: 0000000000000004 lock_is_held include/linux/lockdep.h:249 [inline] lockdep_rtnl_is_held+0x1b/0x40 net/core/rtnetlink.c:182 fib_table_lookup+0xda/0x16e0 net/ipv4/fib_trie.c:1436 __inet_dev_addr_type+0x2d1/0x500 net/ipv4/fib_frontend.c:226 __inet_bind+0x135/0xa90 net/ipv4/af_inet.c:501 kernel_bind+0x13e/0x1c0 net/socket.c:3547 rds_tcp_conn_path_connect+0x53e/0x930 net/rds/tcp_connect.c:175 rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176 process_one_work kernel/workqueue.c:3275 [inline] process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439 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