INFO: task udevd:4355 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:24816 pid: 4355 ppid: 3563 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: 0033:0x7f097d7f3407 RSP: 002b:00007fffbede2fb0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f097d705880 RCX: 00007f097d7f3407 RDX: 00000000000a0800 RSI: 000055f775f531f0 RDI: ffffffffffffff9c RBP: 000055f775f38910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055f775f6ca20 R13: 000055f775f50410 R14: 0000000000000000 R15: 000055f775f6ca20 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 2 locks held by getty/3948: #0: ffff88802c1ed098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cf62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 2 locks held by kworker/0:3/4176: #0: ffff888016c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90002d0fd00 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 1 lock held by udevd/4347: #0: ffff8881475f0118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 1 lock held by udevd/4355: #0: ffff888021124518 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x157/0xa60 block/bdev.c:820 3 locks held by kworker/1:9/4581: #0: ffff888016c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc9000357fd00 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline] #2: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3a5/0x750 kernel/rcu/tree_exp.h:845 3 locks held by kworker/u4:17/8232: 1 lock held by syz-executor/8966: #0: ffff888077e100e0 (&type->s_umount_key#65){++++}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 2 locks held by syz.0.814/9783: #0: ffff8881475f0118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xf9/0x7d0 block/bdev.c:915 #1: ffff88814763a468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2071 2 locks held by dhcpcd/9797: #0: ffff88805ebd7410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:787 [inline] #0: ffff88805ebd7410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:650 [inline] #0: ffff88805ebd7410 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x90/0x240 net/socket.c:1345 #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #1: ffffffff8c323528 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x2d1/0x750 kernel/rcu/tree_exp.h:845 2 locks held by dhcpcd-run-hook/9821: ============================================= 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 01/24/2026 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: 4347 Comm: udevd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xc/0x60 kernel/kcov.c:206 Code: 89 fb e8 17 00 00 00 48 8b 3d 20 bb 10 0c 48 89 de 5b e9 37 42 44 00 00 00 cc cc 00 00 cc 48 8b 04 24 65 48 8b 0d 74 4d 89 7e <65> 8b 15 75 4d 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 RSP: 0018:ffffc900012efae0 EFLAGS: 00000246 RAX: ffffffff81b08b19 RBX: dffffc0000000000 RCX: ffff888076a83b80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffff88807e166b8f R09: ffff88807e166b80 R10: dffffc0000000000 R11: ffffed100fc2cd72 R12: 0000000000000000 R13: 0000000000000000 R14: ffff888073e59d88 R15: ffff888073e59d68 FS: 00007f097d705880(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f097cda4000 CR3: 000000002559a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vma_compute_subtree_gap mm/mmap.c:322 [inline] validate_mm_rb+0x1c9/0x230 mm/mmap.c:386 vma_rb_insert mm/mmap.c:458 [inline] __vma_link_rb+0x54b/0x570 mm/mmap.c:657 __vma_link mm/mmap.c:683 [inline] vma_link+0xbb/0x200 mm/mmap.c:697 __mmap_region mm/mmap.c:1853 [inline] mmap_region+0x1405/0x1650 mm/mmap.c:2933 do_mmap+0x819/0xe90 mm/mmap.c:1586 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:551 ksys_mmap_pgoff+0x140/0x790 mm/mmap.c:1635 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: 0033:0x7f097d869822 Code: 00 00 00 0f 1f 44 00 00 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 3b 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 76 5b 5d c3 0f 1f 00 48 8b 05 a1 35 0d 00 64 RSP: 002b:00007fffbedddb18 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f097d869822 RDX: 0000000000000003 RSI: 0000000000000200 RDI: 0000000000000000 RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 0000000000000018 R13: 0000000000000200 R14: 000055f775f460b0 R15: 0000000000fff000