INFO: task udevd:4178 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:24592 pid: 4178 ppid: 3562 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 io_schedule+0x7c/0xd0 kernel/sched/core.c:8503 wait_on_page_bit_common+0x83b/0xe50 mm/filemap.c:1356 wait_on_page_bit mm/filemap.c:1417 [inline] wait_on_page_locked include/linux/pagemap.h:688 [inline] wait_on_page_read mm/filemap.c:3437 [inline] do_read_cache_page+0xb05/0x1030 mm/filemap.c:3480 read_mapping_page include/linux/pagemap.h:515 [inline] read_part_sector+0xd4/0x4f0 block/partitions/core.c:726 adfspart_check_ICS+0xc3/0xe40 block/partitions/acorn.c:360 check_partition block/partitions/core.c:148 [inline] blk_add_partitions block/partitions/core.c:611 [inline] bdev_disk_changed+0x933/0x16c0 block/partitions/core.c:697 blkdev_get_whole+0x2f9/0x390 block/bdev.c:682 blkdev_get_by_dev+0x2d0/0xa60 block/bdev.c:827 blkdev_open+0x12d/0x2c0 block/fops.c:466 do_dentry_open+0x7ff/0xf80 fs/open.c:826 do_open fs/namei.c:3616 [inline] path_openat+0x26f5/0x2fa0 fs/namei.c:3750 do_filp_open+0x1e2/0x410 fs/namei.c:3777 do_sys_openat2+0x150/0x4b0 fs/open.c:1255 do_sys_open fs/open.c:1271 [inline] __do_sys_openat fs/open.c:1287 [inline] __se_sys_openat fs/open.c:1282 [inline] __x64_sys_openat+0x135/0x160 fs/open.c:1282 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f3e25ca9407 RSP: 002b:00007ffceea34300 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f3e25bbb880 RCX: 00007f3e25ca9407 RDX: 00000000000a0800 RSI: 0000564e120b8670 RDI: ffffffffffffff9c RBP: 0000564e120ad910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000564e120b5650 R13: 0000564e120c5410 R14: 0000000000000000 R15: 0000564e120b5650 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 4 locks held by udevd/3562: 2 locks held by getty/3952: #0: ffff88802c7c4098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900026562e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 1 lock held by udevd/4178: #0: ffff888020d3ed18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 2 locks held by syz-executor/4186: 2 locks held by udevd/4567: #0: ffff8880208b5518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff888146db8468 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0xaa/0xb90 drivers/block/loop.c:1366 2 locks held by kworker/u4:10/7507: 2 locks held by syz.9.1908/10166: #0: ffff8880208c7d18 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff8880209db468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071 1 lock held by dhcpcd-run-hook/10184: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 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+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10185 Comm: dhcpcd-run-hook Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:lock_release+0x0/0x8a0 kernel/locking/lockdep.c:5631 Code: 80 c1 03 38 c1 0f 8c c1 f8 ff ff 48 89 df e8 d7 aa 60 00 e9 b4 f8 ff ff bb 2f 00 00 00 e9 ca f8 ff ff 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 RSP: 0000:ffffc9000354f798 EFLAGS: 00000046 RAX: 1ffff11017206bc4 RBX: ffffffff8be30820 RCX: ffffffff962d9f03 RDX: dffffc0000000000 RSI: ffffffff81b3f47b RDI: ffff8880b9035df8 RBP: ffffc9000354f9b0 R08: ffffea00016148f7 R09: 1ffffd40002c291e R10: dffffc0000000000 R11: fffff940002c291f R12: ffffea00016148c0 R13: 0000000000000000 R14: 0000000000000202 R15: ffffc9000354fa08 FS: 00007f8ca7a5fc80(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055950734dc7c CR3: 0000000067120000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rmqueue_pcplist mm/page_alloc.c:3710 [inline] rmqueue mm/page_alloc.c:3742 [inline] get_page_from_freelist+0x1547/0x1ca0 mm/page_alloc.c:4189 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146 wp_page_copy+0x24b/0x2050 mm/memory.c:3056 handle_pte_fault mm/memory.c:4668 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x1f06/0x4410 mm/memory.c:4883 do_user_addr_fault+0x489/0xc80 arch/x86/mm/fault.c:1355 handle_page_fault arch/x86/mm/fault.c:1443 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1496 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7f8ca7d4f878 Code: fc ff 41 ff ce 49 8b 45 00 75 11 89 a8 08 03 00 00 48 89 df 6a 01 5e e8 92 b0 ff ff 8b 43 1c 8d 50 01 48 c1 e0 04 48 03 43 10 <89> 53 1c 48 93 49 8b 45 00 83 4b 04 ff 48 83 c0 48 80 3d 7f a0 07 RSP: 002b:00007ffd2164a910 EFLAGS: 00010206 RAX: 000055950734dc60 RBX: 000055950734dc60 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000000027ca R08: 00007f8ca7cfab60 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 000055950735b0b0 R13: 00007f8ca7dc9460 R14: 0000000000000002 R15: 0000000000000000