INFO: task udevd:21575 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:22416 pid:21575 tgid:21575 ppid:5186 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 io_schedule+0x8a/0xf0 kernel/sched/core.c:8109 folio_wait_bit_common+0x414/0xa70 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1492 [inline] do_read_cache_folio+0x3bc/0x6b0 mm/filemap.c:4088 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xd1/0x370 block/partitions/core.c:724 adfspart_check_POWERTEC+0x8a/0x630 block/partitions/acorn.c:450 check_partition block/partitions/core.c:143 [inline] blk_add_partitions block/partitions/core.c:591 [inline] bdev_disk_changed+0x7a3/0x1250 block/partitions/core.c:695 blkdev_get_whole+0x187/0x290 block/bdev.c:756 bdev_open+0x2c7/0xe40 block/bdev.c:965 blkdev_open+0x34e/0x4f0 block/fops.c:697 do_dentry_open+0x6d8/0x1660 fs/open.c:947 vfs_open+0x82/0x3f0 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4858 do_file_open+0x20e/0x430 fs/namei.c:4887 do_sys_openat2+0x10d/0x1e0 fs/open.c:1364 do_sys_open fs/open.c:1370 [inline] __do_sys_openat fs/open.c:1386 [inline] __se_sys_openat fs/open.c:1381 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1381 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f496c4a7407 RSP: 002b:00007ffddc5a6a60 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f496cba9880 RCX: 00007f496c4a7407 RDX: 00000000000a0800 RSI: 0000562e0f212180 RDI: ffffffffffffff9c RBP: 0000562e0efbc2c0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000562e0f215cb0 R13: 0000562e0f1f78d0 R14: 0000000000000000 R15: 0000562e0f215cb0 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e7e6ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e7e6ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e7e6ee0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by getty/5572: #0: ffff8880343400a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x419/0x14f0 drivers/tty/n_tty.c:2211 10 locks held by kworker/1:7/5938: 4 locks held by udevd/21539: #0: ffff88803687f638 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:225 [inline] #1: ffff8880b8424648 (psi_seq){-.-.}-{0:0}, at: __schedule+0x2d69/0x6820 kernel/sched/core.c:7182 #2: ffffffff9b223e48 (&____s->seqcount#2){----}-{0:0}, at: clockevents_program_event+0x23e/0x7e0 kernel/time/clockevents.c:360 #3: ffffffff8e7e6ee0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #3: ffffffff8e7e6ee0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #3: ffffffff8e7e6ee0 (rcu_read_lock){....}-{1:3}, at: ep_pm_stay_awake_rcu+0x21/0x270 fs/eventpoll.c:724 1 lock held by udevd/21575: #0: ffff888027f86350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0x41a/0xe40 block/bdev.c:953 2 locks held by syz.0.5385/26493: #0: ffff88802bc5e0d8 (&type->s_umount_key#96/1){+.+.}-{4:4}, at: alloc_super+0x244/0xd20 fs/super.c:345 #1: ffff888027f86350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xa2/0xe40 block/bdev.c:953 3 locks held by kworker/0:6/26867: #0: ffff88813feaf140 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc9000f03fd08 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffffffff8e7f28f8 (rcu_state.barrier_mutex){+.+.}-{4:4} , at: rcu_barrier+0x48/0x6d0 kernel/rcu/tree.c:3828 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 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+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xd18/0x1040 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 96 8a 02 e9 83 42 03 00 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 83 cc 15 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df0 EFLAGS: 00000246 RAX: 0000000008bfb793 RBX: ffff88801e6f2500 RCX: ffffffff8b95c045 RDX: 0000000000000000 RSI: ffffffff8df4de55 RDI: ffffffff8c1be760 RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170a67ad R10: ffff8880b8533d6b R11: 0000000000000000 R12: 0000000000000001 R13: ffffed1003cde4a0 R14: 0000000000000001 R15: ffffffff90db9010 FS: 0000000000000000(0000) GS:ffff8881243f8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd9295e92f8 CR3: 000000002a661000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x464/0x590 kernel/sched/idle.c:352 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x148