INFO: task udevd:29038 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:25840 pid:29038 tgid:29038 ppid:4977 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 io_schedule+0x7f/0xd0 kernel/sched/core.c:8154 folio_wait_bit_common+0x836/0xbc0 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1498 [inline] do_read_cache_folio+0x1ac/0x590 mm/filemap.c:4128 read_mapping_folio include/linux/pagemap.h:1015 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:724 adfspart_check_POWERTEC+0x9a/0x7a0 block/partitions/acorn.c:451 check_partition block/partitions/core.c:143 [inline] blk_add_partitions block/partitions/core.c:591 [inline] bdev_disk_changed+0x851/0x17a0 block/partitions/core.c:695 blkdev_get_whole+0x372/0x510 block/bdev.c:751 bdev_open+0x324/0xd70 block/bdev.c:960 blkdev_open+0x461/0x600 block/fops.c:672 do_dentry_open+0x816/0x1380 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1052 do_open fs/namei.c:4700 [inline] path_openat+0x2e44/0x3830 fs/namei.c:4863 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd468aa7407 RSP: 002b:00007ffc4776ebd0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fd469155880 RCX: 00007fd468aa7407 RDX: 00000000000a0800 RSI: 000055b5c86be540 RDI: ffffffffffffff9c RBP: 000055b5c86a7910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055b5c86c8910 R13: 000055b5c86b5190 R14: 0000000000000000 R15: 000055b5c86c8910 Showing all locks held in the system: 3 locks held by kworker/u8:0/12: #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b06c140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90000117c40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 1 lock held by khungtaskd/30: #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5365: #0: ffff8880369380a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 3 locks held by kworker/u8:24/18182: #0: ffff888032a16140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff888032a16140 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000526fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000526fc40 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #2: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x19/0x30 net/ipv6/addrconf.c:4770 3 locks held by kworker/u9:1/18757: #0: ffff888068646140 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff888068646140 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004267c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004267c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff888060e70ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331 1 lock held by udevd/29038: #0: ffff888027214350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948 3 locks held by kworker/u9:0/727: #0: ffff888041fb8140 ((wq_completion)hci1){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff888041fb8140 ((wq_completion)hci1){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc9000511fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc9000511fc40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffff88801b728ea0 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1cb/0x3f0 net/bluetooth/hci_sync.c:331 3 locks held by kworker/0:0/1791: #0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #0: ffff88801b02b140 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #1: ffffc90004ec7c40 (netdev_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3297 [inline] #1: ffffc90004ec7c40 (netdev_work){+.+.}-{0:0}, at: process_scheduled_works+0xa20/0x14e0 kernel/workqueue.c:3405 #2: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: netdev_work_proc+0x6f/0x770 net/core/netdev_work.c:132 1 lock held by syz.3.8090/6781: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3576 1 lock held by syz.3.8090/6782: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:815 1 lock held by syz.3.8090/6789: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x7a4/0x1150 net/core/dev_ioctl.c:815 2 locks held by syz.6.8091/6795: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4214 #1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #1: ffffffff8eb5ff68 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 2 locks held by syz.6.8091/6801: #0: ffffffff9000a220 (vlan_ioctl_mutex){+.+.}-{4:4}, at: sock_ioctl+0x5eb/0x7e0 net/socket.c:1383 #1: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: vlan_ioctl_handler+0xf0/0x630 net/8021q/vlan.c:519 1 lock held by syz.6.8091/6805: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7138 1 lock held by syz.1.8093/6804: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7138 1 lock held by syz.1.8093/6807: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: ip_mroute_setsockopt+0x137/0x10d0 net/ipv4/ipmr.c:1422 1 lock held by syz.1.8093/6811: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: ip_mroute_setsockopt+0x137/0x10d0 net/ipv4/ipmr.c:1422 3 locks held by syz.7.8094/6808: #0: ffffffff90099a68 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff888078b3f6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2410 #2: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_dump_wiphy+0x49/0x6b0 net/wireless/nl80211.c:3776 2 locks held by syz.7.8094/6809: #0: ffffffff90099a68 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1217 #1: ffff888078b3f6e8 (nlk_cb_mutex-GENERIC){+.+.}-{4:4}, at: __netlink_dump_start+0xf4/0x7b0 net/netlink/af_netlink.c:2410 1 lock held by syz.2.8096/6821: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_detach drivers/net/tun.c:650 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: tun_chr_close+0x3e/0x1c0 drivers/net/tun.c:3576 1 lock held by syz.2.8096/6822: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:134 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: dev_ioctl+0x83c/0x1150 net/core/dev_ioctl.c:842 1 lock held by syz.2.8096/6824: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnetlink_rcv_msg+0x767/0xc00 net/core/rtnetlink.c:7138 1 lock held by syz.2.8096/6825: #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:366 [inline] #0: ffffffff900290c0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc10/0x1c30 net/core/rtnetlink.c:4214 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [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:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18175 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Workqueue: bond1 bond_alb_monitor RIP: 0010:lock_acquire+0x6e/0x350 kernel/locking/lockdep.c:5833 Code: 11 83 f8 08 0f 83 83 01 00 00 89 c0 48 0f a3 05 a8 b5 b4 0e 73 0d e8 f1 29 09 00 84 c0 0f 84 ca 01 00 00 83 3d a2 e8 b4 0e 00 <0f> 84 d3 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 5c bc 91 00 RSP: 0018:ffffc9000536eca0 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000202 RDX: 0000000000000000 RSI: ffffffff8c4bbf60 RDI: ffffffff8c4bbf20 RBP: ffffffff8177827f R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000536ee38 R11: ffffffff81b1fc80 R12: 0000000000000002 R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124f4c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6d701eb7c0 CR3: 000000000e946000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_pages_ok+0xad4/0xbd0 mm/page_alloc.c:1584 skb_kfree_head net/core/skbuff.c:1083 [inline] skb_free_head net/core/skbuff.c:1095 [inline] skb_release_data+0x85e/0xab0 net/core/skbuff.c:1122 skb_release_all net/core/skbuff.c:1197 [inline] __kfree_skb+0x5d/0x210 net/core/skbuff.c:1211 kfree_skb_reason include/linux/skbuff.h:1323 [inline] kfree_skb include/linux/skbuff.h:1332 [inline] gre_tap_xmit+0x28d/0x760 net/ipv4/ip_gre.c:787 __netdev_start_xmit include/linux/netdevice.h:5429 [inline] netdev_start_xmit include/linux/netdevice.h:5438 [inline] xmit_one net/core/dev.c:3937 [inline] dev_hard_start_xmit+0x2cd/0x830 net/core/dev.c:3953 sch_direct_xmit+0x257/0x4c0 net/sched/sch_generic.c:372 qdisc_restart net/sched/sch_generic.c:437 [inline] __qdisc_run+0xb11/0x1620 net/sched/sch_generic.c:445 __dev_xmit_skb net/core/dev.c:4264 [inline] __dev_queue_xmit+0x17c9/0x3820 net/core/dev.c:4884 dev_queue_xmit include/linux/netdevice.h:3461 [inline] alb_send_lp_vid+0x348/0x550 drivers/net/bonding/bond_alb.c:949 alb_send_learning_packets+0x12c/0x300 drivers/net/bonding/bond_alb.c:1012 bond_alb_monitor+0x3d0/0x1820 drivers/net/bonding/bond_alb.c:1563 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245