syzbot
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: 401d, last: 12d
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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 |
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▼
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-....: (10499 ticks this GP) idle=43d4/1/0x4000000000000000 softirq=11826/11828 fqs=5164
rcu: hardirqs softirqs csw/system
rcu: number: 1126509 0 0
rcu: cputime: 18266 34223 38 ==> 52510(ms)
rcu: (t=10502 jiffies g=10369 q=1280 ncpus=2)
CPU: 0 PID: 5940 Comm: syz.0.24 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:rcu_read_unlock_special+0x83/0x4d0 kernel/rcu/tree_plugin.h:763
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 5e a3 91 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:ffffc90000007b00 EFLAGS: 00000206
RAX: d0fb6ebb80bc5c00 RBX: 1ffff92000000f64 RCX: d0fb6ebb80bc5c00
RDX: dffffc0000000000 RSI: ffffffff8acacce0 RDI: ffffffff8b1d35e0
RBP: ffffc90000007be0 R08: ffffffff8e8c8daf R09: 1ffffffff1d191b5
R10: dffffc0000000000 R11: fffffbfff1d191b6 R12: ffffffff8d137300
R13: dffffc0000000000 R14: ffff8880b8e3d190 R15: 1ffff110171c7a32
FS: 000055558326f500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000001b192 CR3: 000000002c396000 CR4: 00000000003506f0
Call Trace:
<IRQ>
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
ieee80211_rx_napi+0x241/0x3c0 net/mac80211/rx.c:5463
ieee80211_rx include/net/mac80211.h:4971 [inline]
ieee80211_handle_queued_frames+0x105/0x190 net/mac80211/main.c:319
tasklet_action_common+0x2d4/0x460 kernel/softirq.c:809
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:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7011
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 a1 db c4 f6 e8 fc d6 f5 f6 fb bf 01 00 00 00 <e8> 31 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc900033a7800 EFLAGS: 00000286
RAX: d0fb6ebb80bc5c00 RBX: 0000000000000000 RCX: d0fb6ebb80bc5c00
RDX: dffffc0000000000 RSI: ffffffff8acacce0 RDI: 0000000000000001
RBP: ffffc900033a78a0 R08: ffffffff8e8c8daf R09: 1ffffffff1d191b5
R10: dffffc0000000000 R11: fffffbfff1d191b6 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000674f00
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:arch_stack_walk+0x12a/0x190 arch/x86/kernel/stacktrace.c:27
Code: ff 44 89 fe e8 07 6a 54 00 45 85 ff 74 46 4c 8d bd 78 ff ff ff 4c 89 ff e8 03 96 08 00 49 89 c4 31 ff 48 89 c6 e8 76 6a 54 00 <4d> 85 e4 74 2c 48 89 df 4c 89 e6 41 ff d6 84 c0 74 26 4c 89 ff e8
RSP: 0018:ffffc900033a7968 EFLAGS: 00000293
RAX: ffffffff81331c3a RBX: ffffc900033a7a20 RCX: ffff88802bcf8000
RDX: 0000000000000000 RSI: ffffffff8aa000d0 RDI: 0000000000000000
RBP: ffffc900033a79f0 R08: ffff88802bcf8000 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000000 R12: ffffffff8aa000d0
R13: ffff88802bcf8000 R14: ffffffff81761ea0 R15: ffffc900033a7968
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:46
__kasan_record_aux_stack+0xaf/0xc0 mm/kasan/generic.c:492
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: 0033:0x7f3ff779e159
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:00007ffd2ffefc88 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: ffffffffffffffda RBX: 00007ffd2ffefd70 RCX: 00007f3ff779e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000001b192 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2c520000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3ff7a25fac R14: 00007f3ff7a25fa8 R15: 00007f3ff7a25fa0
</TASK>
Struck through repros no longer work on HEAD.