INFO: rcu detected stall in flock

Kernel	Title	Rank 🛈	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-5.15	INFO: rcu detected stall in flock	1				1	116d	116d	0/3	auto-obsoleted due to no activity on 2026/01/12 22:11
upstream	INFO: rcu detected stall in flock (2) bpf	1				1	362d	362d	0/29	auto-obsoleted due to no activity on 2025/05/02 07:58

rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-...D } 2690 jiffies s: 51957 root: 0x2/. rcu: blocking rcu_node structures (internal RCU debug): Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 19364 Comm: udevd Not tainted 6.2.0-rc8-syzkaller-00127-gdbeed98d89ea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/21/2023 RIP: 0010:check_preemption_disabled+0xa/0x170 lib/smp_processor_id.c:13 Code: 1f 44 00 00 0f 0b 0f 1f 44 00 00 5b e9 6f fb ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 56 41 55 49 89 f5 41 54 55 <48> 89 fd 53 0f 1f 44 00 00 65 44 8b 25 b1 ea f8 75 65 8b 1d a6 ea RSP: 0018:ffffc900001e0d70 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8a4c4e60 RDI: ffffffff8aa6cc80 RBP: ffffffff8c7921e0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880792157c0 R13: ffffffff8a4c4e60 R14: 00000000ffffffff R15: ffff8880792161f8 FS: 00007f7736c91840(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe73d5a960 CR3: 000000001fd8a000 CR4: 0000000000350ee0 Call Trace: <IRQ> lockdep_recursion_finish kernel/locking/lockdep.c:466 [inline] lock_is_held_type+0xdb/0x140 kernel/locking/lockdep.c:5712 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3e/0x70 kernel/rcu/update.c:125 trace_hrtimer_start include/trace/events/timer.h:198 [inline] debug_activate kernel/time/hrtimer.c:476 [inline] enqueue_hrtimer+0x328/0x470 kernel/time/hrtimer.c:1084 __run_hrtimer kernel/time/hrtimer.c:1702 [inline] __hrtimer_run_queues+0xc71/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x320/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0x180/0x640 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x92/0xc0 arch/x86/kernel/apic/apic.c:1107 </IRQ> <TASK> asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:183 [inline] RIP: 0010:unwind_next_frame+0x1c4/0x1d00 arch/x86/kernel/unwind_orc.c:467 Code: 00 00 00 81 49 c1 ef 08 41 8d 43 ff 41 39 c7 0f 83 e3 13 00 00 48 b8 00 00 00 00 00 fc ff df 44 89 fa 48 8d 3c 95 f4 57 a2 8f <48> 89 f9 48 c1 e9 03 0f b6 0c 01 48 89 f8 83 e0 07 83 c0 03 38 c8 RSP: 0018:ffffc9000377f710 EFLAGS: 00000287 RAX: dffffc0000000000 RBX: 0000000000000001 RCX: 1ffffffff2387740 RDX: 0000000000003856 RSI: 1ffff920006efefc RDI: ffffffff8fa3394c RBP: ffffc9000377f818 R08: ffffffff8c606500 R09: ffffc9000377f7d0 R10: fffff520006eff05 R11: 0000000000094001 R12: ffffc9000377f805 R13: ffffc9000377f7d0 R14: ffffffff81385659 R15: 0000000000003856 __unwind_start+0x51f/0x800 arch/x86/kernel/unwind_orc.c:736 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0x60/0xf0 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x90/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 __kasan_slab_alloc+0x82/0x90 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slab.h:761 [inline] slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x1e4/0x430 mm/slub.c:3476 kmem_cache_zalloc include/linux/slab.h:710 [inline] locks_alloc_lock fs/locks.c:270 [inline] flock_lock_inode+0x16e/0xfe0 fs/locks.c:1023 flock_lock_inode_wait+0xf5/0x230 fs/locks.c:2033 locks_lock_inode_wait fs/locks.c:2060 [inline] locks_lock_file_wait include/linux/fs.h:1365 [inline] __do_sys_flock+0x498/0x510 fs/locks.c:2130 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7736dace77 Code: eb 85 48 8b 15 02 f0 0c 00 f7 d8 64 89 02 b8 ff ff ff ff eb dd 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 b8 49 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d d1 ef 0c 00 f7 d8 64 89 01 48 RSP: 002b:00007ffe73d1d1a8 EFLAGS: 00000202 ORIG_RAX: 0000000000000049 RAX: ffffffffffffffda RBX: 000055ee94ae0d50 RCX: 00007f7736dace77 RDX: 00000000000a0800 RSI: 0000000000000005 RDI: 0000000000000008 RBP: 000055ee94ae0d50 R08: 00000000ffffffff R09: 00007ffe73d56080 R10: 0000000000000000 R11: 0000000000000202 R12: 000055ee94ae6ee0 R13: 000055ee94adf320 R14: 0000000000000008 R15: 000055ee94abb910 </TASK>