INFO: task udevd:10323 blocked for more than 143 seconds. Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:udevd state:D stack:23272 pid:10323 tgid:10323 ppid:5207 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6917 __mutex_lock_common kernel/locking/mutex.c:678 [inline] __mutex_lock+0x805/0x10c0 kernel/locking/mutex.c:746 bdev_open+0xf7/0xcd0 block/bdev.c:907 blkdev_open+0x38e/0x4e0 block/fops.c:652 do_dentry_open+0xdee/0x1960 fs/open.c:956 vfs_open+0x3b/0x370 fs/open.c:1086 do_open fs/namei.c:3880 [inline] path_openat+0x2caf/0x35d0 fs/namei.c:4039 do_filp_open+0x284/0x4e0 fs/namei.c:4066 do_sys_openat2+0x12b/0x1d0 fs/open.c:1429 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x249/0x2a0 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f67757169a4 RSP: 002b:00007fffd675dc10 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f67757169a4 RDX: 0000000000080000 RSI: 000056538e513990 RDI: 00000000ffffff9c RBP: 000056538e513990 R08: 000056538e5128b0 R09: 00007f67757f1c10 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000080000 R13: 000056538e5128b0 R14: 0000000000000000 R15: 0000000000000001 Showing all locks held in the system: 2 locks held by kworker/u8:1/13: #0: ffff88801d307948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801d307948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffff8880b8623b08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41f/0x7a0 kernel/sched/psi.c:987 1 lock held by kdevtmpfs/26: #0: ffff888140490950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #0: ffff888140490950 (&type->i_mutex_dir_key/1){+.+.}-{4:4}, at: __kern_path_locked+0x1ca/0x430 fs/namei.c:2765 1 lock held by khungtaskd/31: #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8ed3df20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6764 2 locks held by getty/5590: #0: ffff88803740a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033532f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x5bb/0x1700 drivers/tty/n_tty.c:2222 3 locks held by kworker/u8:13/5976: 1 lock held by udevd/10323: #0: ffff88802603b358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xf7/0xcd0 block/bdev.c:907 1 lock held by syz.7.1195/10332: #0: ffff88802603b358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_reread_partitions drivers/block/loop.c:435 [inline] #0: ffff88802603b358 (&disk->open_mutex){+.+.}-{4:4}, at: loop_set_status+0x7be/0xb20 drivers/block/loop.c:1243 2 locks held by kworker/u8:16/12063: #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b081148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90004c27c60 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004c27c60 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 1 lock held by syz.3.1765/12758: 2 locks held by sed/12785: 1 lock held by modprobe/12786: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:274 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:437 kthread+0x7b9/0x940 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 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: 12788 Comm: modprobe Not tainted 6.15.0-rc3-syzkaller-00019-gbc3372351d0c #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:lock_acquire+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1 Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000395ed08 EFLAGS: 00000206 RAX: e059293c90275900 RBX: ffffffff8ed3df20 RCX: e059293c90275900 RDX: 0000000000000000 RSI: ffffffff8e4db4cf RDI: ffffffff8ca1b6c0 RBP: ffffffff93686020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4e831380d0 CR3: 0000000063e80000 CR4: 0000000000350ef0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd5/0x23b0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4161 [inline] slab_alloc_node mm/slub.c:4210 [inline] kmem_cache_alloc_noprof+0x1e1/0x390 mm/slub.c:4217 anon_vma_alloc mm/rmap.c:94 [inline] __anon_vma_prepare+0x117/0x4a0 mm/rmap.c:202 __vmf_anon_prepare mm/memory.c:3432 [inline] vmf_anon_prepare mm/internal.h:415 [inline] do_cow_fault mm/memory.c:5538 [inline] do_fault mm/memory.c:5654 [inline] do_pte_missing mm/memory.c:4160 [inline] handle_pte_fault+0x5388/0x61c0 mm/memory.c:5997 __handle_mm_fault mm/memory.c:6140 [inline] handle_mm_fault+0x1129/0x1bf0 mm/memory.c:6309 do_user_addr_fault arch/x86/mm/fault.c:1388 [inline] handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x2bb/0x920 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:__clear_user arch/x86/include/asm/uaccess_64.h:188 [inline] RIP: 0010:clear_user arch/x86/include/asm/uaccess_64.h:205 [inline] RIP: 0010:padzero fs/binfmt_elf.c:125 [inline] RIP: 0010:elf_load+0x510/0x700 fs/binfmt_elf.c:427 Code: 76 44 64 ff eb 7d bb 00 10 00 00 48 29 eb 48 c7 c7 d2 45 77 8e be b5 00 00 00 e8 fb d2 b4 ff 0f 01 cb 31 c0 48 89 d9 4c 89 e7 aa 0f 1f 00 48 89 cb 0f 01 ca 31 ff 48 89 ce e8 1b 49 64 ff 48 RSP: 0018:ffffc9000395f9b8 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000f30 RCX: 0000000000000f30 RDX: 0000000000000001 RSI: ffffffff8e4db4cf RDI: 00007f4e831380d0 RBP: 00000000000000d0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00007f4e831380d0 R13: ffff888079d9a0a8 R14: 00007f4e83138298 R15: 00007f4e83135000 load_elf_interp+0x445/0xac0 fs/binfmt_elf.c:681 load_elf_binary+0x1aa1/0x28a0 fs/binfmt_elf.c:1240 search_binary_handler fs/exec.c:1778 [inline] exec_binprm fs/exec.c:1810 [inline] bprm_execve+0x9ab/0x1430 fs/exec.c:1862 kernel_execve+0x92e/0xa50 fs/exec.c:2028 call_usermodehelper_exec_async+0x237/0x380 kernel/umh.c:109 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245