INFO: task udevd:26820 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:21064 pid:26820 tgid:26820 ppid:5237 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 io_schedule+0x80/0xd0 kernel/sched/core.c:7903 folio_wait_bit_common+0x6b0/0xb90 mm/filemap.c:1317 folio_put_wait_locked mm/filemap.c:1481 [inline] do_read_cache_folio+0x1aa/0x590 mm/filemap.c:3939 read_mapping_folio include/linux/pagemap.h:991 [inline] read_part_sector+0xb6/0x2b0 block/partitions/core.c:722 adfspart_check_POWERTEC+0x8c/0xf30 block/partitions/acorn.c:454 check_partition block/partitions/core.c:141 [inline] blk_add_partitions block/partitions/core.c:589 [inline] bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693 blkdev_get_whole+0x380/0x510 block/bdev.c:748 bdev_open+0x31e/0xd30 block/bdev.c:957 blkdev_open+0x457/0x600 block/fops.c:694 do_dentry_open+0x950/0x13f0 fs/open.c:965 vfs_open+0x3b/0x340 fs/open.c:1095 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1435 do_sys_open fs/open.c:1450 [inline] __do_sys_openat fs/open.c:1466 [inline] __se_sys_openat fs/open.c:1461 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1461 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f17524a7407 RSP: 002b:00007ffd89e60600 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f1752b64880 RCX: 00007f17524a7407 RDX: 00000000000a0800 RSI: 00005599a3368570 RDI: ffffffffffffff9c RBP: 00005599a3367910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005599a3384f10 R13: 00005599a3375190 R14: 0000000000000000 R15: 00005599a3384f10 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13a0e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5636: #0: ffff88814d9260a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 1 lock held by syz-executor/5874: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 1 lock held by udevd/26820: #0: ffff88802504d358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945 5 locks held by syz.1.9284/7932: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148 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: 7926 Comm: syz.1.9284 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0033:0x7f9e2dc681a1 Code: 11 0c 24 48 8b 77 f8 48 89 f8 48 89 eb eb 12 66 2e 0f 1f 84 00 00 00 00 00 48 8b 4b 08 48 83 c3 08 48 39 d1 72 f3 48 83 e8 08 <48> 39 f2 73 17 66 2e 0f 1f 84 00 00 00 00 00 48 8b 70 f8 48 83 e8 RSP: 002b:00007ffe43fcee80 EFLAGS: 00000202 RAX: 00007f9e2d2208d0 RBX: 00007f9e2d217e28 RCX: ffffffff82021fb0 RDX: ffffffff82010e01 RSI: ffffffff820105ec RDI: 00007f9e2d2675d8 RBP: 00007f9e2d1dcff8 R08: 00007f9e2d2222e0 R09: 00007f9e2dfd2000 R10: 00007f9e2cffb008 R11: 000000000000001a R12: 00007f9e2d1dcff0 R13: 000000000000001c R14: 00007ffe43fcf008 R15: 00007f9e2cffb008 FS: 0000555583ca8500 GS: 0000000000000000