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: 383d, last: 7d23h
▶ ▼ 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 495d 495d 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 error 7 9d13h 202d 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 error 1 56d 56d 0/3 upstream: reported syz repro on 2026/07/06 21:37
linux-6.1 INFO: rcu detected stall in sys_close_range 1 syz, C done 3 353d 546d 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 229d 302d 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-....: (10501 ticks this GP) idle=8afc/1/0x4000000000000000 softirq=12801/12801 fqs=5198
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1371947          0            0
rcu: 	cputime:    16640      35859           42   ==> 52510(ms)
rcu: 	(t=10502 jiffies g=12281 q=1592 ncpus=2)
CPU: 0 PID: 5988 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:84 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:127 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:178 [inline]
RIP: 0010:kasan_check_range+0x97/0x290 mm/kasan/generic.c:187
Code: 49 83 fc 10 7f 29 4d 85 e4 0f 84 3d 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 0f 85 8d 01 00 00 49 ff c3 48 ff c3 75 ee <e9> 1d 01 00 00 44 89 dd 83 e5 07 0f 84 b5 00 00 00 41 80 3b 00 4d
RSP: 0018:ffffc90000006cf0 EFLAGS: 00000256
RAX: ffffffff813bd201 RBX: 0000000000000000 RCX: ffffffff813bd28e
RDX: 0000000000000001 RSI: 0000000000000060 RDI: ffffc90000006da8
RBP: 0000000000000000 R08: ffffc90000006e07 R09: 1ffff92000000dc0
R10: dffffc0000000000 R11: fffff52000000dc1 R12: 000000000000000c
R13: ffff888030f49e00 R14: fffff52000000dc1 R15: 1ffff92000000db5
FS:  00005555609c0500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000001ed51 CR3: 0000000075baa000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 __asan_memset+0x22/0x40 mm/kasan/shadow.c:84
 __unwind_start+0x3e/0x730 arch/x86/kernel/unwind_orc.c:688
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xf8/0x190 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843
 skb_kfree_head net/core/skbuff.c:946 [inline]
 skb_free_head net/core/skbuff.c:958 [inline]
 skb_release_data+0x609/0x7f0 net/core/skbuff.c:988
 skb_release_all net/core/skbuff.c:1054 [inline]
 __kfree_skb net/core/skbuff.c:1068 [inline]
 kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1104
 kfree_skb include/linux/skbuff.h:1264 [inline]
 vti6_tnl_xmit+0x13e7/0x19c0 net/ipv6/ip6_vti.c:596
 __netdev_start_xmit include/linux/netdevice.h:4982 [inline]
 netdev_start_xmit include/linux/netdevice.h:4996 [inline]
 xmit_one net/core/dev.c:3649 [inline]
 dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3665
 __dev_queue_xmit+0x198c/0x3640 net/core/dev.c:4472
 neigh_output include/net/neighbour.h:547 [inline]
 ip6_finish_output2+0xe2e/0x1620 net/ipv6/ip6_output.c:141
 dst_output include/net/dst.h:467 [inline]
 NF_HOOK include/linux/netfilter.h:304 [inline]
 ndisc_send_skb+0xbb9/0x1480 net/ipv6/ndisc.c:513
 addrconf_rs_timer+0x36b/0x640 net/ipv6/addrconf.c:4036
 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:check_preemption_disabled+0x5/0x110 lib/smp_processor_id.c:13
Code: ff cc cc cc cc f3 0f 1e fa 48 c7 c7 00 32 1d 8b 48 c7 c6 40 32 1d 8b eb 0c 66 2e 0f 1f 84 00 00 00 00 00 66 90 55 41 57 41 56 <53> 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 65 8b 05
RSP: 0018:ffffc9000250fb40 EFLAGS: 00000283
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816885e7
RDX: 0000000000000000 RSI: ffffffff8b1d3240 RDI: ffffffff8b1d3200
RBP: ffffc9000250fc88 R08: ffffffff8e8c866f R09: 1ffffffff1d190cd
R10: dffffc0000000000 R11: fffffbfff1d190ce R12: 1ffff920004a1f7c
R13: ffffffff8d131e60 R14: 0000000000000000 R15: dffffc0000000000
 rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline]
 rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:700
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0xc6/0x420 kernel/locking/lockdep.c:5725
 rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 rcu_read_lock_sched include/linux/rcupdate.h:878 [inline]
 pfn_valid include/linux/mmzone.h:2011 [inline]
 __virt_addr_valid+0x128/0x380 arch/x86/mm/physaddr.c:65
 kasan_addr_to_slab+0xd/0xd0 mm/kasan/common.c:36
 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:477
 task_work_add+0xdd/0x470 kernel/task_work.c:82
 fput+0xdd/0x1a0 fs/file_table.c:474
 filp_close+0x10f/0x150 fs/open.c:1548
 __range_close fs/file.c:698 [inline]
 __close_range+0x379/0x690 fs/file.c:755
 __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: 0033:0x7f01db19e0d9
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:00007fff7a6e9f98 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007fff7a6ea080 RCX: 00007f01db19e0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000001ed51 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2cb20000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f01db425fac R14: 00007f01db425fa8 R15: 00007f01db425fa0
 </TASK>

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.