INFO: task udevd:5980 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:24424 pid:5980 ppid:5156 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 io_schedule+0x80/0xd0 kernel/sched/core.c:9022 folio_wait_bit_common+0x6eb/0xf70 mm/filemap.c:1329 folio_put_wait_locked mm/filemap.c:1493 [inline] do_read_cache_folio+0x1c0/0x7e0 mm/filemap.c:3771 read_mapping_folio include/linux/pagemap.h:898 [inline] read_part_sector+0xd2/0x350 block/partitions/core.c:718 adfspart_check_POWERTEC+0x8d/0xf00 block/partitions/acorn.c:454 check_partition block/partitions/core.c:138 [inline] blk_add_partitions block/partitions/core.c:600 [inline] bdev_disk_changed+0x73a/0x1410 block/partitions/core.c:689 blkdev_get_whole+0x30d/0x390 block/bdev.c:655 blkdev_get_by_dev+0x279/0x600 block/bdev.c:797 blkdev_open+0x152/0x360 block/fops.c:589 do_dentry_open+0x8c6/0x1500 fs/open.c:929 do_open fs/namei.c:3632 [inline] path_openat+0x274b/0x3190 fs/namei.c:3789 do_filp_open+0x1c5/0x3d0 fs/namei.c:3816 do_sys_openat2+0x12c/0x1c0 fs/open.c:1419 do_sys_open fs/open.c:1434 [inline] __do_sys_openat fs/open.c:1450 [inline] __se_sys_openat fs/open.c:1445 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1445 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ffaf62a7407 RSP: 002b:00007fff5e5c7d60 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffaf6987880 RCX: 00007ffaf62a7407 RDX: 00000000000a0800 RSI: 0000563dcbe49f00 RDI: ffffffffffffff9c RBP: 0000563dcbe33910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000563dcbe63e90 R13: 0000563dcbe4b410 R14: 0000000000000000 R15: 0000563dcbe63e90 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by getty/5547: #0: ffff88814cd060a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 4 locks held by udevd/5824: #0: ffff8880b8f3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8f289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694 #2: ffff88807d241958 (&ep->lock){....}-{2:2}, at: ep_poll_callback+0xd5/0xae0 fs/eventpoll.c:1212 #3: ffff88807d2418a8 (&ep->wq){....}-{2:2}, at: __wake_up_common_lock kernel/sched/wait.c:137 [inline] #3: ffff88807d2418a8 (&ep->wq){....}-{2:2}, at: __wake_up_sync_key kernel/sched/wait.c:213 [inline] #3: ffff88807d2418a8 (&ep->wq){....}-{2:2}, at: __wake_up_sync+0xef/0x180 kernel/sched/wait.c:245 1 lock held by udevd/5980: #0: ffff8880218de4c8 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev+0x121/0x600 block/bdev.c:788 4 locks held by kworker/u4:9/6084: #0: ffff8880b8f3c218 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffffc900052efd00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900052efd00 ((work_completion)(&(&nsim_dev->trap_data->trap_report_dw)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff8880b8f29598 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x73b/0xdb0 kernel/time/timer.c:1112 #3: ffffffff970bfc00 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709 1 lock held by dhcpcd-run-hook/15006: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 15007 Comm: dhcpcd-run-hook Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:stack_trace_consume_entry+0x66/0x270 kernel/stacktrace.c:89 Code: 4d 89 f5 49 c1 ed 03 41 0f b6 44 15 00 84 c0 0f 85 1d 01 00 00 45 3b 0e 73 3a 48 8d 5f 0c 49 89 df 49 c1 ef 03 41 0f b6 04 17 <84> c0 0f 85 42 01 00 00 44 8b 23 45 85 e4 74 21 41 ff cc 41 0f b6 RSP: 0018:ffffc900042d7378 EFLAGS: 00000a03 RAX: 0000000000000000 RBX: ffffc900042d748c RCX: ffff888029a01e00 RDX: dffffc0000000000 RSI: ffffffff81dc235e RDI: ffffc900042d7480 RBP: 1ffff9200085ae92 R08: ffffc900042d7490 R09: 0000000000000002 R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff81dc235e R13: 1ffff9200085ae91 R14: ffffc900042d7488 R15: 1ffff9200085ae91 FS: 00007efd1f843c80(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efd1faa77e8 CR3: 000000002f778000 CR4: 00000000003506e0 Call Trace: arch_stack_walk+0x138/0x190 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519 vma_lock_alloc kernel/fork.c:460 [inline] vm_area_dup+0x61/0x270 kernel/fork.c:513 dup_mmap kernel/fork.c:711 [inline] dup_mm kernel/fork.c:1692 [inline] copy_mm+0xc08/0x1c20 kernel/fork.c:1741 copy_process+0x16d3/0x3d70 kernel/fork.c:2506 kernel_clone+0x21b/0x840 kernel/fork.c:2914 __do_sys_clone kernel/fork.c:3057 [inline] __se_sys_clone kernel/fork.c:3041 [inline] __x64_sys_clone+0x18c/0x1e0 kernel/fork.c:3041 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7efd1f9dd636 Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffdc1f6bf50 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffdc1f6bf58 RCX: 00007efd1f9dd636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 000055bd7da1fc30 R08: 0000000000000000 R09: 00000000000000d0 R10: 00007efd1f843f50 R11: 0000000000000246 R12: 000055bd7da2dfc0 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000