INFO: task udevd:5823 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23616 pid:5823 tgid:5823 ppid:5185 task_flags:0x400140 flags:0x00080003 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 io_schedule+0xbf/0x130 kernel/sched/core.c:7871 folio_wait_bit_common+0x3d5/0x9e0 mm/filemap.c:1330 folio_put_wait_locked mm/filemap.c:1494 [inline] do_read_cache_folio+0x342/0x5c0 mm/filemap.c:4018 read_mapping_folio include/linux/pagemap.h:999 [inline] read_part_sector+0xd4/0x370 block/partitions/core.c:722 adfspart_check_POWERTEC+0x8a/0x710 block/partitions/acorn.c:454 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x723/0x1520 block/partitions/core.c:693 blkdev_get_whole+0x187/0x290 block/bdev.c:748 bdev_open+0x2c7/0xe40 block/bdev.c:957 blkdev_open+0x34e/0x4f0 block/fops.c:701 do_dentry_open+0x982/0x1530 fs/open.c:965 vfs_open+0x82/0x3f0 fs/open.c:1097 do_open fs/namei.c:3975 [inline] path_openat+0x1de4/0x2cb0 fs/namei.c:4134 do_filp_open+0x20b/0x470 fs/namei.c:4161 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc719ea7407 RSP: 002b:00007ffff369d530 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fc71a5aa880 RCX: 00007fc719ea7407 RDX: 00000000000a0800 RSI: 0000557bd9239710 RDI: ffffffffffffff9c RBP: 0000557bd8ff12c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000557bd9233d50 R13: 0000557bd922c8d0 R14: 0000000000000000 R15: 0000557bd9233d50 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x36/0x1c0 kernel/locking/lockdep.c:6775 1 lock held by klogd/5174: #0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:646 [inline] #0: ffff8880b843a398 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x7e/0x130 kernel/sched/core.c:631 2 locks held by getty/5571: #0: ffff888031b5b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x41b/0x14f0 drivers/tty/n_tty.c:2222 1 lock held by udevd/5823: #0: ffff8880264ea358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:945 3 locks held by kworker/u8:5/15273: #0: ffff88813ff29948 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3238 #1: ffffc900032e7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3239 #2: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0x51/0xc0 net/core/link_watch.c:303 1 lock held by syz.5.2473/20760: #0: ffff8880264ea358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1288 1 lock held by syz.7.2826/22048: #0: ffff8880264ea358 (&disk->open_mutex){+.+.}-{4:4}, at: sync_bdevs+0xfd/0x360 block/bdev.c:1288 3 locks held by syz-executor/22573: #0: ffffffff8f48eee0 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #0: ffffffff8f48eee0 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #0: ffffffff8f48eee0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x113/0x2c0 net/core/rtnetlink.c:574 #1: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064 #2: ffffffff8e3cfcb8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock+0x284/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by syz.1.2998/22684: #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff900e7408 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x600/0x2000 net/core/rtnetlink.c:4064 1 lock held by syz.4.3002/22705: ============================================= 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 lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 nmi_cpu_backtrace+0x27b/0x390 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x29c/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf3f/0x1170 kernel/hung_task.c:495 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 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: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: d7 6c 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 84 29 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6 RAX: 00000000036a337b RBX: 0000000000000001 RCX: ffffffff8b60a2a9 RDX: 0000000000000000 RSI: ffffffff8da2b882 RDI: ffffffff8bf07040 RBP: ffffed1003adc490 R08: 0000000000000001 R09: ffffed10170a6655 R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801d6e2480 R14: ffffffff90820dd0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124b08000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f80b3db4198 CR3: 000000007d8c4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog