INFO: task udevd:16648 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:26664 pid:16648 tgid:16648 ppid:4986 task_flags:0x400140 flags:0x00080802 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:1323 folio_put_wait_locked mm/filemap.c:1492 [inline] do_read_cache_folio+0x1ac/0x590 mm/filemap.c:4122 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:4859 do_file_open+0x23e/0x4a0 fs/namei.c:4888 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: 0033:0x7f25762a7407 RSP: 002b:00007fff98907b80 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f257621d880 RCX: 00007f25762a7407 RDX: 00000000000a0800 RSI: 0000563ec09578f0 RDI: ffffffffffffff9c RBP: 0000563ec0943910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000563ec0958830 R13: 0000563ec0951190 R14: 0000000000000000 R15: 0000563ec0958830 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8eb59c20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5374: #0: ffff888035ea90a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900032332e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45a/0x1360 drivers/tty/n_tty.c:2211 1 lock held by udevd/16648: #0: ffff8880256bb350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xde/0xd70 block/bdev.c:948 2 locks held by syz.4.5311/26615: 1 lock held by dhcpcd-run-hook/26657: ============================================= 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 05/09/2026 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: 5604 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:__wrmsrq arch/x86/include/asm/msr.h:80 [inline] RIP: 0010:arch_inlined_clockevent_set_next_coupled arch/x86/include/asm/clock_inlined.h:19 [inline] RIP: 0010:clockevent_set_next_coupled kernel/time/clockevents.c:318 [inline] RIP: 0010:clockevents_program_event+0x1b9/0x630 kernel/time/clockevents.c:360 Code: 3c 24 4c 89 fe e8 27 b9 fc ff 84 c0 0f 84 da 00 00 00 e8 0a ca 0f 00 48 8b 44 24 40 48 89 c2 48 c1 ea 20 b9 e0 06 00 00 0f 30 <4c> 8b 64 24 10 43 c6 44 2c 04 f8 31 c0 48 c7 44 24 20 0e 36 e0 45 RSP: 0018:ffffc90003a1fb00 EFLAGS: 00000006 RAX: 0000019a213f543e RBX: ffff8880b8623c80 RCX: 00000000000006e0 RDX: 000000000000019a RSI: 0000000000000014 RDI: 0000000000000040 RBP: ffffc90003a1fbc0 R08: ffffffff81b3611e R09: 0000000000080000 R10: 0000000000000000 R11: ffffffff9a7b9748 R12: ffff8880b8623cc8 R13: dffffc0000000000 R14: 0000000000000004 R15: 000000b7da6fb61b FS: 000055556c76c540(0000) GS:ffff888124f60000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000057a030 CR3: 0000000074154000 CR4: 00000000003526f0 Call Trace: hrtimer_start_range_ns_user+0x1d7/0x430 kernel/time/hrtimer.c:1581 hrtimer_start_expires_user include/linux/hrtimer.h:248 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:2319 [inline] do_nanosleep+0x16c/0x6a0 kernel/time/hrtimer.c:2396 hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2445 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1406 [inline] __se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1383 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: 0033:0x7faeacd58fd7 Code: 48 89 fa 4c 89 df e8 a8 56 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007ffdbb35c3c0 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 000055556c76c540 RCX: 00007faeacd58fd7 RDX: 00007ffdbb35c400 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffdbb35c8e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007ffdbb35c43c R14: 00007ffdbb35c4d0 R15: 0000000000000000