INFO: rcu detected stall in sys_close_range (2)

Status: upstream: reported C repro on 2026/07/06 21:37
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+941a3734ead118eee304@syzkaller.appspotmail.com
First crash: 97d, last: 20h21m
Fix bisection: failed (error log)
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2026/10/07 linux-5.15.y (ToT) a051a4bf909f C [report] INFO: rcu detected stall in smp_call_function
2026/10/06 upstream (ToT) 69f80fef3153 C Didn't crash
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in close_range fs 1 1 536d 536d 0/29 auto-obsoleted due to no activity on 2025/07/22 12:43
linux-6.1 INFO: rcu detected stall in sys_close_range (2) origin:lts-only 1 syz, C inconclusive 8 13d 243d 0/3 upstream: reported C repro on 2026/02/10 20:38
linux-6.1 INFO: rcu detected stall in sys_close_range 1 syz, C done 3 393d 587d 0/3 auto-obsoleted due to no activity on 2025/12/22 06:21
linux-6.6 INFO: rcu detected stall in sys_close_range origin:lts-only 1 syz, C inconclusive 15 19d 424d 0/2 upstream: reported C repro on 2025/08/13 16:29
linux-5.15 INFO: rcu detected stall in sys_close_range 1 syz error 3 269d 343d 0/3 auto-obsoleted due to no activity on 2026/07/02 02:05

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 GPs behind) idle=355/1/0x4000000000000002 softirq=7921/7923 fqs=2079 
	(detected by 1, t=10505 jiffies, g=7833, q=2326)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4486 Comm: syz.1.131 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:201
Code: 2e 0f 1f 84 00 00 00 00 00 90 53 48 89 fb e8 17 00 00 00 48 8b 3d 80 0c 12 0c 48 89 de 5b e9 47 6b 44 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d 14 5b 89 7e 65 8b 15 15 5b 89 7e 81 e2 00
RSP: 0018:ffffc90000007138 EFLAGS: 00000002
RAX: 000000000000a301 RBX: ffff88807b9835b8 RCX: 614b9a8c43c58800
RDX: 0000000000000100 RSI: ffffffff8a7a48a0 RDI: ffffffff8a7a4860
RBP: ffffc90000007258 R08: dffffc0000000000 R09: 1ffffffff203e218
R10: dffffc0000000000 R11: fffffbfff203e219 R12: 0000000000000001
R13: 1ffff92000000e2c R14: ffffc900000071e0 R15: ffffc90000007340
FS:  000055556c621500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000019a86 CR3: 0000000024f16000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock include/linux/rcupdate.h:741 [inline]
 __perf_event_output kernel/events/core.c:7810 [inline]
 perf_event_output_forward+0xe8/0x2e0 kernel/events/core.c:7832
 __perf_event_overflow+0x35f/0x550 kernel/events/core.c:9525
 perf_tp_event+0x324/0xbe0 kernel/events/core.c:10057
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10031
 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 42 0b 9d 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: 614b9a8c43c58800 RBX: 1ffff92000000ef4 RCX: 614b9a8c43c58800
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a48c0
RBP: ffffc90000007860 R08: ffffffff901f11c7 R09: 1ffffffff203e238
R10: dffffc0000000000 R11: fffffbfff203e239 R12: ffffffff8c323400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 ndisc_send_skb+0xd3b/0x1410 net/ipv6/ndisc.c:521
 addrconf_rs_timer+0x367/0x640 net/ipv6/addrconf.c:3966
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:preempt_schedule_irq+0xb6/0x160 kernel/sched/core.c:6799
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 d7 88 f7 e8 80 bf b5 f7 fb bf 01 00 00 00 <e8> d5 b5 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc9000308fb40 EFLAGS: 00000286
RAX: 614b9a8c43c58800 RBX: 0000000000000000 RCX: 614b9a8c43c58800
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: 0000000000000001
RBP: ffffc9000308fbf0 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000611f68
 irqentry_exit+0x63/0x70 kernel/entry/common.c:435
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5673
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000308fcb8 EFLAGS: 00000206
RAX: 614b9a8c43c58800 RBX: ffff88807b040000 RCX: 614b9a8c43c58800
RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a48c0
RBP: 0000000000000000 R08: ffff88807b040007 R09: 1ffff1100f608000
R10: dffffc0000000000 R11: ffffed100f608001 R12: dffffc0000000000
R13: 0000000000000246 R14: ffffffff8c31efc0 R15: 00000000ffffffff
 lock_is_held include/linux/lockdep.h:287 [inline]
 ___might_sleep+0x9b/0x610 kernel/sched/core.c:9624
 __range_close fs/file.c:693 [inline]
 __close_range+0x262/0x510 fs/file.c:747
 __do_sys_close_range fs/open.c:1410 [inline]
 __se_sys_close_range fs/open.c:1407 [inline]
 __x64_sys_close_range+0x76/0x80 fs/open.c:1407
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5cdaa6a159
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:00007ffe3a241888 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007ffe3a241970 RCX: 00007f5cdaa6a159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000019a86 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b30e20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5cdacf1fac R14: 00007f5cdacf1fa8 R15: 00007f5cdacf1fa0
 </TASK>

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/28 04:41 linux-5.15.y 0248c33e835e a3c7249d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_close_range
2026/10/11 02:47 linux-5.15.y a051a4bf909f 4f92358f .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_close_range
2026/09/30 01:29 linux-5.15.y 0248c33e835e 328436b3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_close_range
2026/09/05 09:57 linux-5.15.y 0996e0926f6b 4f7b22a0 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_close_range
2026/07/06 21:36 linux-5.15.y c86c4726e7f0 88b240e4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_close_range
* Struck through repros no longer work on HEAD.