INFO: rcu detected stall in sys_close (2)

Status: upstream: reported on 2026/06/20 04:40
Reported-by: syzbot+8d76ca4f73bf1c160804@syzkaller.appspotmail.com
First crash: 66d, last: 2d20h
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_close (3) kernel 1 1 1460d 1460d 0/29 auto-obsoleted due to no activity on 2022/10/25 14:50
linux-5.15 INFO: rcu detected stall in sys_close (2) 1 1 281d 281d 0/3 auto-obsoleted due to no activity on 2026/02/25 04:01
upstream INFO: rcu detected stall in sys_close (4) fs 1 1 1383d 1383d 0/29 auto-obsoleted due to no activity on 2023/02/13 19:04
linux-5.15 INFO: rcu detected stall in sys_close 1 1 849d 849d 0/3 auto-obsoleted due to no activity on 2024/08/05 21:33
linux-6.6 INFO: rcu detected stall in close origin:lts-only 1 syz, C error 2 238d 258d 0/2 upstream: reported C repro on 2025/12/10 03:57
upstream INFO: rcu detected stall in sys_close (7) prio:high fs 1 syz, C error 23 5d14h 858d 0/29 upstream: reported C repro on 2024/04/19 01:14
linux-5.15 INFO: rcu detected stall in sys_close (3) 1 1 18d 18d 0/3 upstream: reported on 2026/08/07 05:33
linux-6.1 INFO: rcu detected stall in sys_close origin:lts-only 1 syz, C done 1 263d 295d 3/3 fixed on 2026/01/11 15:32
upstream INFO: rcu detected stall in sys_close fs 1 1 1697d 1697d 0/29 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in sys_close (6) fs 1 3 957d 1038d 0/29 auto-obsoleted due to no activity on 2024/04/10 05:01
upstream INFO: rcu detected stall in sys_close (2) fs 1 3 1555d 1605d 0/29 auto-closed as invalid on 2022/08/21 03:13
upstream INFO: rcu detected stall in sys_close (5) net 1 syz, C done 1 1092d 1092d 23/29 fixed on 2023/10/12 12:48

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2661 jiffies s: 115441 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: 19469 Comm: syz.4.3939 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:kasan_check_range+0x1b0/0x290 mm/kasan/generic.c:-1
Code: f3 4d 01 f3 49 89 df 49 8d 5f 07 4d 85 ff 49 0f 49 df 48 83 e3 f8 49 29 df 74 0e 41 80 3b 00 75 69 49 ff c3 49 ff cf 75 f2 5b <41> 5c 41 5e 41 5f 5d c3 45 84 ff 0f 85 91 00 00 00 41 f7 c7 00 ff
RSP: 0018:ffffc90006526a18 EFLAGS: 00000056
RAX: 0000000000000001 RBX: 0000000000000016 RCX: ffffffff8164128a
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff90b12240
RBP: ffffc90006526c70 R08: ffffffff90b12247 R09: 1ffffffff2162448
R10: dffffc0000000000 R11: fffffbfff2162449 R12: dffffc0000000001
R13: ffff888089d70000 R14: 1ffffffff2162448 R15: 0000000000000001
FS:  00007f8f14ce86c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000011000 CR3: 000000002a02a000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 hlock_class kernel/locking/lockdep.c:228 [inline]
 __lock_acquire+0x138a/0x7c40 kernel/locking/lockdep.c:5060
 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5676
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock_sched include/linux/rcupdate.h:883 [inline]
 pfn_valid include/linux/mmzone.h:1857 [inline]
 __virt_addr_valid+0x1a5/0x540 arch/x86/mm/physaddr.c:65
 kasan_addr_to_slab+0x9/0xc0 mm/kasan/common.c:36
 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471
 irq_work_queue_on+0x10f/0x260 kernel/irq_work.c:140
 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 __perf_event_output kernel/events/core.c:7741 [inline]
 perf_event_output_forward+0x271/0x2f0 kernel/events/core.c:7750
 __perf_event_overflow+0x457/0x630 kernel/events/core.c:9496
 perf_swevent_overflow kernel/events/core.c:9579 [inline]
 perf_swevent_event+0x315/0x570 kernel/events/core.c:9630
 perf_tp_event+0x36b/0xc10 kernel/events/core.c:10064
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10032
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
RIP: 0010:preempt_schedule_irq+0xb6/0x160 kernel/sched/core.c:6875
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 7f bf 01 00 00 00 e8 15 32 1f f7 e8 f0 09 4f f7 fb bf 01 00 00 00 <e8> 25 ba ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc900065276a0 EFLAGS: 00000286
RAX: d07390a72cb72600 RBX: 0000000000000000 RCX: d07390a72cb72600
RDX: dffffc0000000000 RSI: ffffffff8a8c1820 RDI: 0000000000000001
RBP: ffffc90006527750 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000ca4ed4
 irqentry_exit+0x63/0x70 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:preempt_schedule_notrace+0x1/0x120 kernel/sched/core.c:6797
Code: d8 48 c1 e8 03 42 80 3c 38 00 0f 84 5a ff ff ff 48 89 df e8 11 d8 99 f7 e9 4d ff ff ff 5b 41 5e 41 5f c3 66 0f 1f 44 00 00 55 <48> 89 e5 41 57 41 56 53 48 83 e4 e0 48 83 ec 60 65 48 8b 04 25 28
RSP: 0018:ffffc90006527818 EFLAGS: 00000246
RAX: d07390a72cb72600 RBX: ffff8880591d2618 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffffc90006527870 R08: ffffffff8e2118af R09: 1ffffffff1c42315
R10: dffffc0000000000 R11: fffffbfff1c42316 R12: 1ffff92000ca4f1c
R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff92000ca4f1c
 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0x8c2/0x920 kernel/locking/lockdep.c:5687
 rcu_lock_release include/linux/rcupdate.h:355 [inline]
 rcu_read_unlock include/linux/rcupdate.h:824 [inline]
 is_bpf_text_address+0x28b/0x2a0 kernel/bpf/core.c:738
 kernel_text_address+0x9c/0xd0 kernel/extable.c:125
 __kernel_text_address+0x9/0x30 kernel/extable.c:79
 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323
 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0xa6/0xf0 kernel/stacktrace.c:122
 kasan_save_stack+0x3a/0x60 mm/kasan/common.c:46
 __kasan_record_aux_stack+0xb2/0xc0 mm/kasan/generic.c:486
 task_work_add+0x7f/0x330 kernel/task_work.c:48
 fput+0xd9/0x1a0 fs/file_table.c:376
 filp_close+0x108/0x150 fs/open.c:1439
 __do_sys_close fs/open.c:1452 [inline]
 __se_sys_close fs/open.c:1450 [inline]
 __x64_sys_close+0x34/0x70 fs/open.c:1450
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f8f13d9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8f14ce8028 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f8f14025fa0 RCX: 00007f8f13d9e0d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f8f13e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8f14026038 R14: 00007f8f14025fa0 R15: 00007fff4a0579a8
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/22 18:08 linux-6.1.y 7e6e67054721 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_close
2026/06/20 04:39 linux-6.1.y fdb6fcb41cc7 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_close
* Struck through repros no longer work on HEAD.