INFO: rcu detected stall in sys_close_range

Status: upstream: reported C repro on 2025/08/13 16:29
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+793af646fd66df0b254e@syzkaller.appspotmail.com
First crash: 424d, last: 19d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/12/22 linux-6.6.y (ToT) 5fa4793a2d2d C [report] INFO: rcu detected stall in smp_call_function
2025/12/22 upstream (ToT) 9448598b22c5 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-5.15 INFO: rcu detected stall in sys_close_range (2) origin:lts-only 1 syz, C error 5 20h49m 97d 0/3 upstream: reported C repro on 2026/07/06 21:37
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-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
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2026/01/04 23:24 2h33m fix candidate upstream OK (0) job log
2025/11/19 15:50 2h26m (2) fix candidate upstream OK (0) job log

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (1 GPs behind) idle=573c/1/0x4000000000000000 softirq=13613/13614 fqs=4255
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1527795          0            0
rcu: 	cputime:    17321      35158           62   ==> 52480(ms)
rcu: 	(t=10500 jiffies g=12141 q=1469 ncpus=2)
CPU: 0 PID: 5934 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline]
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
RIP: 0010:unwind_next_frame+0x49a/0x2990 arch/x86/kernel/unwind_orc.c:494
Code: 4c 89 6c 24 40 4c 8b 74 24 50 48 89 d8 4c 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4d 8d 7c 45 00 4c 89 f8 <48> c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 34
RSP: 0018:ffffc90000007478 EFLAGS: 00000206
RAX: ffffffff8e9eeda8 RBX: ffffffff8e9eedb4 RCX: 0000000000000006
RDX: 0000000000000100 RSI: ffffffff81770466 RDI: ffffffff817704b7
RBP: ffffffff8e9eed9c R08: ffffc90000007610 R09: 0000000000000007
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff817704b7
R13: ffffffff8e9eed9c R14: ffffffff81770466 R15: ffffffff8e9eeda8
FS:  0000555581db5500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000001b5c3 CR3: 000000007a5d5000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 __kfence_alloc+0x2d7/0x3d0 mm/kfence/core.c:1133
 kfence_alloc include/linux/kfence.h:129 [inline]
 slab_alloc_node mm/slub.c:3481 [inline]
 kmem_cache_alloc_node+0x299/0x310 mm/slub.c:3540
 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562
 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
 alloc_skb include/linux/skbuff.h:1316 [inline]
 new_skb drivers/block/aoe/aoecmd.c:66 [inline]
 aoecmd_cfg_pkts drivers/block/aoe/aoecmd.c:430 [inline]
 aoecmd_cfg+0x2c5/0xa50 drivers/block/aoe/aoecmd.c:1374
 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x570/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x27d/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:lock_acquire+0x208/0x420 kernel/locking/lockdep.c:5760
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc90003377ce0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 463b1c55351d2a00
RDX: 0000000000000000 RSI: ffffffff8acade60 RDI: ffffffff8b1d3ba0
RBP: ffffc90003377df8 R08: dffffc0000000000 R09: 1ffffffff223d6a3
R10: dffffc0000000000 R11: fffffbfff223d6a4 R12: 1ffff9200066efa8
R13: ffff888026ae2298 R14: 0000000000000246 R15: dffffc0000000000
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
 __close_range+0x211/0x690 fs/file.c:-1
 __do_sys_close_range fs/open.c:1600 [inline]
 __se_sys_close_range fs/open.c:1597 [inline]
 __x64_sys_close_range+0x7a/0x90 fs/open.c:1597
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f47ba59e159
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:00007ffd62dafa08 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007ffd62dafaf0 RCX: 00007f47ba59e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000001b5c3 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2c220000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f47ba825fac R14: 00007f47ba825fa8 R15: 00007f47ba825fa0
 </TASK>

Crashes (15):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/22 01:46 linux-6.6.y 79643295eba1 853b104b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/09/06 00:02 linux-6.6.y 8b73de7da85f 4f7b22a0 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/08/24 10:31 linux-6.6.y dc6160265ffc 1e72964b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/08/24 06:20 linux-6.6.y dc6160265ffc 1e72964b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/07/31 03:46 linux-6.6.y a1153c0deb44 aaffb173 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/07/28 20:57 linux-6.6.y c5596480c50e edc8a875 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/07/04 12:35 linux-6.6.y d1cfde2d5d15 fcece630 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/06/26 06:13 linux-6.6.y d1cfde2d5d15 7ff32d8b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/05/27 06:44 linux-6.6.y 0a40c6fbd105 2b01f00e .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/05/01 14:16 linux-6.6.y 258cf62a6dfd 753c55b9 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/04/07 05:23 linux-6.6.y 80de0a958133 4440e7c2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/03/25 02:17 linux-6.6.y 4fc00fe35d46 74e70d19 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2026/02/05 06:43 linux-6.6.y 2cf6f68313dc ea10c935 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2025/12/22 09:05 linux-6.6.y 5fa4793a2d2d d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
2025/08/13 16:29 linux-6.6.y 3a8ababb8b6a 22ec1469 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-6-6-kasan-perf INFO: rcu detected stall in sys_close_range
* Struck through repros no longer work on HEAD.