INFO: task udevd:5872 blocked 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:21488 pid:5872 tgid:5872 ppid:1 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x80/0xd0 kernel/sched/core.c:7903 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317 folio_put_wait_locked mm/filemap.c:1481 [inline] do_read_cache_folio+0x1aa/0x590 mm/filemap.c:3939 read_mapping_folio include/linux/pagemap.h:991 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_POWERTEC+0x8c/0xf30 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+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:748 bdev_open+0x31e/0xd30 block/bdev.c:957 blkdev_open+0x3a8/0x510 block/fops.c:691 do_dentry_open+0x950/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f419dca7407 RSP: 002b:00007ffc7d18c710 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f419e392880 RCX: 00007f419dca7407 RDX: 00000000000a0800 RSI: 0000560c72849320 RDI: ffffffffffffff9c RBP: 0000560c7283e910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000560c72853830 R13: 0000560c7284c190 R14: 0000000000000000 R15: 0000560c72853830 INFO: lockdep is turned off. NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 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] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 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: 96 Comm: kworker/0:1H Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: kblockd blk_mq_timeout_work RIP: 0010:debug_lockdep_rcu_enabled+0xf/0x40 kernel/rcu/update.c:320 Code: cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d 57 a8 29 04 00 74 1e <83> 3d 7a d8 29 04 00 74 15 65 48 8b 0c 25 08 80 a0 92 31 c0 83 b9 RSP: 0018:ffffc90000007670 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffffffff90341601 RCX: ffffc90000007f68 RDX: ffffc90000007701 RSI: dffffc0000000000 RDI: ffffc90000007750 RBP: dffffc0000000000 R08: ffffc90000007f50 R09: 0000000000000000 R10: ffffc90000007798 R11: fffff52000000ef5 R12: ffffc90000007f60 R13: ffffc90000000000 R14: ffffc90000007748 R15: ffffffff8172c195 FS: 0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c302e82 CR3: 000000004a79c000 CR4: 00000000003526f0 Call Trace: rcu_read_unlock include/linux/rcupdate.h:869 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x195c/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 insert_work+0x3d/0x330 kernel/workqueue.c:2184 __queue_work+0xbaf/0xfb0 kernel/workqueue.c:2343 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1793 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x646/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449 Code: 85 32 01 00 00 e8 c1 86 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 b0 86 1f 00 eb 06 e8 a9 86 1f 00 fb 48 c7 c7 80 e1 12 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 b9 35 RSP: 0018:ffffc900026170e0 EFLAGS: 00000293 RAX: ffffffff81a02487 RBX: ffffffff81a02344 RCX: ffff88801df91e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e12e180 RBP: ffffc900026171f0 R08: ffffffff8fa38637 R09: 1ffffffff1f470c6 R10: dffffc0000000000 R11: fffffbfff1f470c7 R12: dffffc0000000000 R13: 1ffff920004c2e20 R14: 0000000000000200 R15: 0000000000000060 dev_vprintk_emit+0x337/0x3f0 drivers/base/core.c:4914 dev_printk_emit+0xe0/0x130 drivers/base/core.c:4925 _dev_info+0x10a/0x160 drivers/base/core.c:4983 nbd_xmit_timeout+0x832/0xb30 drivers/block/nbd.c:520 blk_mq_rq_timed_out block/blk-mq.c:1635 [inline] blk_mq_handle_expired+0x16f/0x2c0 block/blk-mq.c:1703 bt_iter+0x2f0/0x3c0 block/blk-mq-tag.c:292 __sbitmap_for_each_set include/linux/sbitmap.h:269 [inline] sbitmap_for_each_set+0x301/0x5e0 include/linux/sbitmap.h:290 bt_for_each block/blk-mq-tag.c:324 [inline] blk_mq_queue_tag_busy_iter+0x43b/0x770 block/blk-mq-tag.c:533 blk_mq_timeout_work+0x1d6/0x3e0 block/blk-mq.c:1745 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245