INFO: task udevd:5783 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:23048 pid:5783 ppid:5138 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 io_schedule+0x80/0xd0 kernel/sched/core.c:9023 folio_wait_bit_common+0x714/0xfa0 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7d0 mm/filemap.c:3786 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x340 block/partitions/core.c:718 adfspart_check_POWERTEC+0x93/0xed0 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:600 [inline] bdev_disk_changed+0x740/0x1420 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:672 blkdev_get_by_dev+0x279/0x600 block/bdev.c:814 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3640 [inline] path_openat+0x27f1/0x3230 fs/namei.c:3797 do_filp_open+0x1f5/0x430 fs/namei.c:3824 do_sys_openat2+0x134/0x1d0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f62ccaa7407 RSP: 002b:00007ffe65bee660 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f62cd163880 RCX: 00007f62ccaa7407 RDX: 00000000000a0800 RSI: 000056172ad7c520 RDI: ffffffffffffff9c RBP: 000056172ad7b910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000056172ad8ee20 R13: 000056172ad89190 R14: 0000000000000000 R15: 000056172ad8ee20 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: 1 lock held by khungtaskd/29: #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d132060 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:3/50: 2 locks held by getty/5532: #0: ffff88802d2ae0a0 (&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+0x433/0x1390 drivers/tty/n_tty.c:2217 1 lock held by udevd/5783: #0: ffff8880220424c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 2 locks held by udevd/5929: 1 lock held by udevd/9410: #0: ffff88802210b4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:805 2 locks held by kworker/0:9/16721: #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #0: ffff888017c72538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 #1: ffffc9000b687d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2628 [inline] #1: ffffc9000b687d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2730 2 locks held by dhcpcd/22133: #0: ffff888025136130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline] #0: ffff888025136130 (sk_lock-AF_PACKET){+.+.}-{0:0}, at: packet_do_bind+0x32/0xcc0 net/packet/af_packet.c:3258 #1: ffffffff8d137a38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #1: ffffffff8d137a38 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004 1 lock held by udevadm/22149: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf3d/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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 22149 Comm: udevadm Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:60 [inline] RIP: 0010:unwind_next_frame+0x1cc6/0x2970 arch/x86/kernel/unwind_orc.c:665 Code: 3c 28 00 74 08 4c 89 ff e8 87 f8 a3 00 49 8b 07 4c 39 f3 0f 96 c1 4c 39 f0 0f 97 c2 84 d1 74 3c 49 8d 4e 08 48 39 d9 0f 96 c2 <48> 39 c1 0f 97 c0 49 39 ee 0f 97 c3 08 c3 08 d3 4c 89 f7 48 89 ee RSP: 0018:ffffc900034078d8 EFLAGS: 00000206 RAX: ffffc90003408000 RBX: ffffc90003400000 RCX: ffffc90003407e50 RDX: ffff888056b00000 RSI: 0000000000000001 RDI: ffffc900034079b0 RBP: ffffc90003407e10 R08: ffff888056b00000 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000000 R12: ffffc900034079a8 R13: dffffc0000000000 R14: ffffc90003407e48 R15: ffffc900034079b8 FS: 00007f3bda7da880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f527e6a0700 CR3: 000000006158e000 CR4: 00000000003506e0 Call Trace: arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1e0 mm/slub.c:3843 kernfs_fop_release+0x166/0x190 fs/kernfs/file.c:828 __fput+0x234/0x970 fs/file_table.c:384 __do_sys_close fs/open.c:1573 [inline] __se_sys_close+0x15f/0x220 fs/open.c:1558 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3bda115a67 Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8 RSP: 002b:00007ffeb5f5d328 EFLAGS: 00000297 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 000055ee9f0632a0 RCX: 00007f3bda115a67 RDX: 00007f3bda1efea0 RSI: 000055ee9f074a30 RDI: 0000000000000005 RBP: 00007f3bda1efff0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000 R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544 vkms_vblank_simulate: vblank timer overrun vkms_vblank_simulate: vblank timer overrun