INFO: task udevd:22796 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:22088 pid:22796 tgid:22796 ppid:4995 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 io_schedule+0x7f/0xd0 kernel/sched/core.c:8110 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1324 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4089 read_mapping_folio include/linux/pagemap.h:1017 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:724 adfspart_check_POWERTEC+0x9a/0x7a0 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+0x817/0x1770 block/partitions/core.c:695 blkdev_get_whole+0x380/0x510 block/bdev.c:756 bdev_open+0x31e/0xd30 block/bdev.c:965 blkdev_open+0x470/0x610 block/fops.c:697 do_dentry_open+0x822/0x13a0 fs/open.c:947 vfs_open+0x3b/0x340 fs/open.c:1079 do_open fs/namei.c:4699 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4858 do_file_open+0x23e/0x4a0 fs/namei.c:4887 do_sys_openat2+0x113/0x200 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+0x138/0x170 fs/open.c:1381 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: 0033:0x7fe1254a7407 RSP: 002b:00007ffde33e1790 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fe125bce880 RCX: 00007fe1254a7407 RDX: 00000000000a0800 RSI: 0000563c35f162d0 RDI: ffffffffffffff9c RBP: 0000563c35f15910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000563c35f28e20 R13: 0000563c35f23190 R14: 0000000000000000 R15: 0000563c35f28e20 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95cce0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5386: #0: ffff888037d370a0 (&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+0x45c/0x13a0 drivers/tty/n_tty.c:2211 4 locks held by kworker/1:6/5819: #0: ffff88801aeaad40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3289 [inline] #0: ffff88801aeaad40 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3397 #1: ffffc90004fd7c40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3290 [inline] #1: ffffc90004fd7c40 ((work_completion)(&(&ssp->srcu_sup->work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3397 #2: ffffffff8e95dbc8 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: srcu_advance_state kernel/rcu/srcutree.c:1813 [inline] #2: ffffffff8e95dbc8 (&ssp->srcu_sup->srcu_gp_mutex){+.+.}-{4:4}, at: process_srcu+0x6e/0x1650 kernel/rcu/srcutree.c:1973 #3: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #3: ffffffff8e962fe8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961 1 lock held by udevd/22796: #0: ffff888027c8f350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953 1 lock held by syz.2.8674/2345: ============================================= 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 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 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+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x389/0x470 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: 5609 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:get_timespec64+0x0/0x1b0 kernel/time/time.c:869 Code: 14 00 49 be ff ff ff ff ff ff ff 7f 31 db eb a2 e8 45 f5 f4 09 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 RSP: 0018:ffffc90003a2fe18 EFLAGS: 00000282 RAX: dffffc0000000000 RBX: 1ffffffff179f18e RCX: ffff88807b8e9f00 RDX: 0000000000000000 RSI: 00007ffe7cb31db0 RDI: ffffc90003a2fe60 RBP: ffffc90003a2fee0 R08: ffffc90003a2fe6f R09: 0000000000000000 R10: ffffc90003a2fe60 R11: fffff52000745fce R12: 1ffff92000745fc8 R13: ffffffff8bcf8c70 R14: 0000000000000000 R15: ffffc90003a2fe60 FS: 00005555733ca540(0000) GS:ffff8881252a4000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd1e91ea2f8 CR3: 0000000022f44000 CR4: 00000000003526f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __do_sys_clock_nanosleep kernel/time/posix-timers.c:1380 [inline] __se_sys_clock_nanosleep+0x1ce/0x3b0 kernel/time/posix-timers.c:1368 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: 0033:0x7f66bb357fd7 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:00007ffe7cb31d70 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 00005555733ca540 RCX: 00007f66bb357fd7 RDX: 00007ffe7cb31db0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffe7cb32290 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007ffe7cb31dec R14: 00007ffe7cb31e80 R15: 0000000000000000 ---------------- Code disassembly (best guess): 0: 14 00 adc $0x0,%al 2: 49 be ff ff ff ff ff movabs $0x7fffffffffffffff,%r14 9: ff ff 7f c: 31 db xor %ebx,%ebx e: eb a2 jmp 0xffffffb2 10: e8 45 f5 f4 09 call 0x9f4f55a 15: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: 90 nop 24: 90 nop 25: 90 nop 26: 90 nop 27: 90 nop 28: 90 nop 29: 90 nop * 2a: f3 0f 1e fa endbr64 <-- trapping instruction 2e: 55 push %rbp 2f: 48 89 e5 mov %rsp,%rbp 32: 41 57 push %r15 34: 41 56 push %r14 36: 41 55 push %r13 38: 41 54 push %r12 3a: 53 push %rbx 3b: 48 83 e4 e0 and $0xffffffffffffffe0,%rsp 3f: 48 rex.W