udevd[5203]: inotify_add_watch(7, /dev/loop2p2, 10) failed: No such file or directory ====================================================== WARNING: possible circular locking dependency detected 6.6.0-rc4-next-20231005-syzkaller #0 Not tainted ------------------------------------------------------ udevd/5203 is trying to acquire lock: ffff8880660227b8 (&p->pi_lock){-.-.}-{2:2}, at: class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] ffff8880660227b8 (&p->pi_lock){-.-.}-{2:2}, at: try_to_wake_up+0xb0/0x15d0 kernel/sched/core.c:4213 but task is already holding lock: ffffffff8cb98e18 ((console_sem).lock){-...}-{2:2}, at: up+0x16/0xb0 kernel/locking/semaphore.c:187 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 ((console_sem).lock){-...}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 down_trylock+0x12/0x70 kernel/locking/semaphore.c:139 __down_trylock_console_sem+0x40/0x140 kernel/printk/printk.c:323 console_trylock+0x73/0x130 kernel/printk/printk.c:2652 console_trylock_spinning kernel/printk/printk.c:1924 [inline] vprintk_emit+0x162/0x5f0 kernel/printk/printk.c:2303 vprintk+0x7b/0x90 kernel/printk/printk_safe.c:45 _printk+0xc8/0x100 kernel/printk/printk.c:2329 pick_eevdf kernel/sched/fair.c:963 [inline] check_preempt_wakeup_fair+0x553/0x640 kernel/sched/fair.c:8108 wakeup_preempt+0x125/0x320 kernel/sched/core.c:2217 ttwu_do_activate+0x24f/0xd90 kernel/sched/core.c:3767 ttwu_queue kernel/sched/core.c:4008 [inline] try_to_wake_up+0x6bc/0x15d0 kernel/sched/core.c:4329 hrtimer_wakeup+0x47/0x60 kernel/time/hrtimer.c:1942 __run_hrtimer kernel/time/hrtimer.c:1688 [inline] __hrtimer_run_queues+0x203/0xc10 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1063 [inline] __sysvec_apic_timer_interrupt+0x105/0x3f0 arch/x86/kernel/apic/apic.c:1080 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1074 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 on_stack arch/x86/include/asm/stacktrace.h:60 [inline] stack_access_ok+0x1df/0x270 arch/x86/kernel/unwind_orc.c:393 deref_stack_reg arch/x86/kernel/unwind_orc.c:403 [inline] unwind_next_frame+0x1a98/0x2390 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0xfa/0x170 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x15b/0x1b0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1800 [inline] slab_free_freelist_hook+0x114/0x1e0 mm/slub.c:1826 slab_free mm/slub.c:3809 [inline] __kmem_cache_free+0xc0/0x180 mm/slub.c:3822 skb_kfree_head net/core/skbuff.c:950 [inline] skb_free_head+0x110/0x1b0 net/core/skbuff.c:962 skb_release_data+0x5ba/0x870 net/core/skbuff.c:992 skb_release_all net/core/skbuff.c:1058 [inline] __kfree_skb net/core/skbuff.c:1072 [inline] consume_skb net/core/skbuff.c:1288 [inline] consume_skb+0xd2/0x170 net/core/skbuff.c:1282 nsim_dev_trap_report drivers/net/netdevsim/dev.c:821 [inline] nsim_dev_trap_report_work+0x872/0xc70 drivers/net/netdevsim/dev.c:850 process_one_work+0x884/0x15c0 kernel/workqueue.c:2630 process_scheduled_works kernel/workqueue.c:2703 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2784 kthread+0x33c/0x440 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 -> #1 (&rq->__lock){-.-.}-{2:2}: _raw_spin_lock_nested+0x31/0x40 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x29/0x130 kernel/sched/core.c:558 raw_spin_rq_lock kernel/sched/sched.h:1357 [inline] rq_lock kernel/sched/sched.h:1671 [inline] task_fork_fair+0x70/0x240 kernel/sched/fair.c:12399 sched_cgroup_fork+0x3cf/0x510 kernel/sched/core.c:4799 copy_process+0x4580/0x74b0 kernel/fork.c:2609 kernel_clone+0xfd/0x920 kernel/fork.c:2907 user_mode_thread+0xb4/0xf0 kernel/fork.c:2985 rest_init+0x27/0x2b0 init/main.c:691 arch_call_rest_init+0x13/0x30 init/main.c:823 start_kernel+0x39f/0x480 init/main.c:1068 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:556 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:537 secondary_startup_64_no_verify+0x166/0x16b -> #0 (&p->pi_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] try_to_wake_up+0xb0/0x15d0 kernel/sched/core.c:4213 up+0x79/0xb0 kernel/locking/semaphore.c:191 __up_console_sem kernel/printk/printk.c:340 [inline] __console_unlock kernel/printk/printk.c:2699 [inline] console_unlock+0x1cf/0x260 kernel/printk/printk.c:3031 vprintk_emit+0x17f/0x5f0 kernel/printk/printk.c:2304 devkmsg_emit.constprop.0+0xc5/0x100 kernel/printk/printk.c:716 devkmsg_write+0x217/0x3d0 kernel/printk/printk.c:779 call_write_iter include/linux/fs.h:1966 [inline] do_iter_readv_writev+0x21e/0x3c0 fs/read_write.c:735 do_iter_write+0x17f/0x820 fs/read_write.c:860 vfs_writev+0x221/0x700 fs/read_write.c:933 do_writev+0x137/0x370 fs/read_write.c:976 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd other info that might help us debug this: Chain exists of: &p->pi_lock --> &rq->__lock --> (console_sem).lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock((console_sem).lock); lock(&rq->__lock); lock((console_sem).lock); lock(&p->pi_lock); *** DEADLOCK *** 1 lock held by udevd/5203: #0: ffffffff8cb98e18 ((console_sem).lock){-...}-{2:2}, at: up+0x16/0xb0 kernel/locking/semaphore.c:187 stack backtrace: CPU: 0 PID: 5203 Comm: udevd Not tainted 6.6.0-rc4-next-20231005-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 check_noncircular+0x311/0x3f0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3868 [inline] __lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5136 lock_acquire kernel/locking/lockdep.c:5753 [inline] lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5718 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 class_raw_spinlock_irqsave_constructor include/linux/spinlock.h:518 [inline] try_to_wake_up+0xb0/0x15d0 kernel/sched/core.c:4213 up+0x79/0xb0 kernel/locking/semaphore.c:191 __up_console_sem kernel/printk/printk.c:340 [inline] __console_unlock kernel/printk/printk.c:2699 [inline] console_unlock+0x1cf/0x260 kernel/printk/printk.c:3031 vprintk_emit+0x17f/0x5f0 kernel/printk/printk.c:2304 devkmsg_emit.constprop.0+0xc5/0x100 kernel/printk/printk.c:716 devkmsg_write+0x217/0x3d0 kernel/printk/printk.c:779 call_write_iter include/linux/fs.h:1966 [inline] do_iter_readv_writev+0x21e/0x3c0 fs/read_write.c:735 do_iter_write+0x17f/0x820 fs/read_write.c:860 vfs_writev+0x221/0x700 fs/read_write.c:933 do_writev+0x137/0x370 fs/read_write.c:976 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f84811a2e03 Code: 89 c7 48 89 44 24 08 e8 6a f2 f9 ff 48 8b 44 24 08 48 83 c4 28 c3 c3 64 8b 04 25 18 00 00 00 85 c0 75 20 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 76 6d 48 8b 15 f6 5f 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffdfddd6318 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f84811a2e03 RDX: 0000000000000005 RSI: 00007ffdfddd6380 RDI: 0000000000000005 RBP: 00007ffdfddd6380 R08: 00007ffdfddd63f7 R09: 00007ffdfddd5c98 R10: 0000000000000002 R11: 0000000000000246 R12: 000000000000001b R13: 00007ffdfddd64a8 R14: 0000000000000000 R15: 00007ffdfddd6408 udevd[5203]: inotify_add_watch(7, /dev/loop2p2, 10) failed: No such file or directory udevd[5203]: inotify_add_watch(7, /dev/loop2p3, 10) failed: No such file or directory udevd[5203]: inotify_add_watch(7, /dev/loop2p7, 10) failed: No such file or directory