INFO: task udevd:5832 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:21368 pid:5832 tgid:5832 ppid:5193 task_flags:0x400140 flags:0x00080802 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x17b4/0x5680 kernel/sched/core.c:7183 __schedule_loop kernel/sched/core.c:7262 [inline] schedule+0x164/0x360 kernel/sched/core.c:7277 io_schedule+0x7f/0xd0 kernel/sched/core.c:8104 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323 folio_put_wait_locked mm/filemap.c:1492 [inline] do_read_cache_folio+0x1ad/0x590 mm/filemap.c:4088 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+0x785/0x14e0 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+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fda93ea7407 RSP: 002b:00007ffd72f3f400 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fda94603880 RCX: 00007fda93ea7407 RDX: 00000000000a0800 RSI: 0000559fcbc20820 RDI: ffffffffffffff9c RBP: 0000559fcbc14910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000559fcbc31f10 R13: 0000559fcbc22190 R14: 0000000000000000 R15: 0000559fcbc31f10 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e95d020 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5580: #0: ffff888032b200a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000322b2e8 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13a0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5832: #0: ffff88802759e350 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:953 3 locks held by kworker/1:8/16798: #0: ffff8880b873aea0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b87271d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline] #2: ffff8880b87271d8 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085 1 lock held by syz.1.5504/25628: #0: ffff888058018840 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1029 [inline] #0: ffff888058018840 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: __sock_release net/socket.c:721 [inline] #0: ffff888058018840 (&sb->s_type->i_mutex_key#13){+.+.}-{4:4}, at: sock_close+0x9b/0x240 net/socket.c:1514 ============================================= NMI backtrace for cpu 0 CPU: 0 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:161 [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:346 [inline] watchdog+0xfaa/0x1000 kernel/hung_task.c:515 kthread+0x388/0x470 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5810 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:__sanitizer_cov_trace_pc+0x5c/0x70 kernel/kcov.c:235 Code: a8 16 00 00 83 fa 02 75 21 48 8b 91 b0 16 00 00 48 8b 32 48 8d 7e 01 8b 89 ac 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 8f e9 f0 09 cc 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 RSP: 0018:ffffc90000a089c8 EFLAGS: 00000006 RAX: ffffffff81b24717 RBX: 1ffff1100f7f7547 RCX: ffff88807bfb9ec0 RDX: 0000000000010100 RSI: ffffffff8e22a959 RDI: ffff88807bfb9ec0 RBP: ffff88802c21d300 R08: ffffffff90321ab7 R09: 1ffffffff2064356 R10: dffffc0000000000 R11: fffffbfff2064357 R12: ffff88807bfbaa38 R13: 1ffff110170e507a R14: ffff8880b8728420 R15: 0000000000000001 FS: 000055557ae71540(0000) GS:ffff888125343000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f715fde92f8 CR3: 0000000078e3e000 CR4: 00000000003526f0 Call Trace: arch_static_branch arch/x86/include/asm/jump_label.h:37 [inline] trace_hrtimer_expire_exit include/trace/events/timer.h:308 [inline] __run_hrtimer kernel/time/hrtimer.c:1933 [inline] __hrtimer_run_queues+0x3e7/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 0d 1c ec f5 f7 c3 00 02 00 00 74 05 e8 10 38 17 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 a4 ad dd f5 65 8b 05 9d d0 87 07 85 c0 74 18 5b 41 5e e9 41 48 RSP: 0018:ffffc90000a08cb8 EFLAGS: 00000206 RAX: 0000000000000006 RBX: 0000000000000296 RCX: 0000000000000101 RDX: 0000000000000000 RSI: ffffffff8dfb7147 RDI: 0000000000000001 RBP: 0000000000000000 R08: ffffffff90321ab7 R09: 1ffffffff2064356 R10: dffffc0000000000 R11: fffffbfff2064357 R12: ffff8880964cfb40 R13: ffff8880964cfaf0 R14: ffffffff9a762d90 R15: 0000000000000001 __debug_check_no_obj_freed lib/debugobjects.c:1125 [inline] debug_check_no_obj_freed+0x52e/0x550 lib/debugobjects.c:1146 slab_free_hook mm/slub.c:2616 [inline] slab_free mm/slub.c:6165 [inline] kmem_cache_free+0xfb/0x630 mm/slub.c:6295 rcu_do_batch kernel/rcu/tree.c:2617 [inline] rcu_core+0x7cd/0x1070 kernel/rcu/tree.c:2869 handle_softirqs+0x22a/0x840 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:aa_current_raw_label security/apparmor/include/cred.h:80 [inline] RIP: 0010:begin_current_label_crit_section security/apparmor/include/cred.h:223 [inline] RIP: 0010:common_file_perm security/apparmor/lsm.c:528 [inline] RIP: 0010:apparmor_file_permission+0x32/0x300 security/apparmor/lsm.c:542 Code: 56 41 55 41 54 53 50 89 74 24 04 48 89 fd 49 bd 00 00 00 00 00 fc ff df e8 0b c3 5a fd e8 b6 bf 48 07 65 4c 8b 35 16 35 d3 0e <49> 81 c6 08 09 00 00 4d 89 f7 49 c1 ef 03 43 80 3c 2f 00 74 08 4c RSP: 0018:ffffc90003a67bf0 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000004 RCX: ffff88807bfb9ec0 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888026007dc0 RBP: ffff888026007dc0 R08: ffff888028ee52c3 R09: 1ffff110051dca58 R10: dffffc0000000000 R11: ffffed10051dca59 R12: ffff888026007dc0 R13: dffffc0000000000 R14: ffff88807bfb9ec0 R15: 0000000000000000 security_file_permission+0x8d/0x260 security/security.c:2392 rw_verify_area+0xbb/0x4d0 fs/read_write.c:475 vfs_read+0x160/0xa70 fs/read_write.c:565 ksys_read+0x150/0x270 fs/read_write.c:717 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2c34f57997 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:00007ffe1807f5b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055557ae71540 RCX: 00007f2c34f57997 RDX: 0000000000000004 RSI: 00007ffe1807f60c RDI: 0000000000000003 RBP: 00007ffe1807fab0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000004 R13: 00007ffe1807f60c R14: 00007ffe1807f6a0 R15: 0000000000000000