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INFO: rcu detected stall in sys_futex (2)

Status: upstream: reported syz repro on 2024/06/05 16:49
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+6ceb9abf06f08ceec1d2@syzkaller.appspotmail.com
First crash: 223d, last: 13d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/01/05 linux-5.15.y (ToT) 91786f140358 C [report] INFO: rcu detected stall in corrupted
2025/01/05 upstream (ToT) ab75170520d4 C Didn't crash
▶ ▼ Similar bugs (9)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_futex (7) kernel 64 2d16h 204d 0/28 upstream: reported on 2024/06/24 16:48
upstream INFO: rcu detected stall in sys_futex (3) kernel 959 1833d 1882d 0/28 auto-closed as invalid on 2020/03/08 12:44
upstream INFO: rcu detected stall in sys_futex (2) kernel 6 2001d 2145d 0/28 auto-closed as invalid on 2019/10/25 14:11
upstream INFO: rcu detected stall in sys_futex (4) kernel 1 1082d 1082d 0/28 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in sys_futex kernel 1 2207d 2207d 0/28 closed as invalid on 2018/12/31 04:10
linux-5.15 INFO: rcu detected stall in sys_futex 4 379d 554d 0/3 auto-obsoleted due to no activity on 2024/04/10 17:08
linux-6.1 INFO: rcu detected stall in sys_futex 17 6d19h 559d 0/3 upstream: reported on 2023/07/05 11:35
upstream INFO: rcu detected stall in sys_futex (5) kernel 12 813d 1058d 0/28 auto-obsoleted due to no activity on 2023/02/12 18:33
upstream INFO: rcu detected stall in sys_futex (6) kernel 10 382d 617d 0/28 auto-obsoleted due to no activity on 2024/03/29 00:57

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-....: (1 GPs behind) idle=945/1/0x4000000000000000 softirq=39720/39724 fqs=5244 
	(detected by 1, t=10502 jiffies, g=43781, q=2939)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 18030 Comm: syz.2.6217 Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:irq_work_single kernel/irq_work.c:154 [inline]
RIP: 0010:irq_work_run_list+0x18c/0x370 kernel/irq_work.c:177
Code: 83 e7 fe 48 89 df be 04 00 00 00 e8 0e 7c 3d 00 43 0f b6 44 35 00 84 c0 49 89 de 0f 85 2d 01 00 00 45 89 3e f0 83 44 24 fc 00 <44> 89 e6 83 e6 08 31 ff e8 87 a1 f3 ff 44 89 e0 83 e0 08 44 89 fb
RSP: 0018:ffffc90000007800 EFLAGS: 00000086
RAX: 0000000000000000 RBX: ffff8880b8e3b1b8 RCX: ffffffff818ce692
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff8880b8e3b1b8
RBP: ffffc900000078d8 R08: dffffc0000000000 R09: ffffed10171c7638
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000023
R13: 1ffff110171c7637 R14: ffff8880b8e3b1b8 R15: 0000000000000022
FS:  00007f2b366de6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000004 CR3: 000000007ae37000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 irq_work_run+0x63/0xe0 kernel/irq_work.c:186
 __sysvec_irq_work+0x9a/0x250 arch/x86/kernel/irq_work.c:22
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x4a/0xc0 arch/x86/kernel/irq_work.c:17
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x520 kernel/rcu/tree_plugin.h:671
Code: f1 f1 f1 00 f2 f2 f2 49 89 04 17 66 41 c7 44 17 09 f3 f3 41 c6 44 17 0b f3 65 44 8b 25 6d 82 96 7e 41 f7 c4 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 3a 00 00 00 00 66 42 c7 44 3a
RSP: 0018:ffffc900000079e0 EFLAGS: 00000206
RAX: 19d4ac874b3ac100 RBX: 1ffff92000000f44 RCX: ffffffff96a8ff03
RDX: dffffc0000000000 RSI: ffffffff8aab2b80 RDI: ffffffff8af9f000
RBP: ffffc90000007ab8 R08: ffffffff81870508 R09: ffffed10171c765a
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8cb23d00
R13: ffff88801e078458 R14: ffffc90000007a20 R15: 1ffff92000000f40
 __rcu_read_unlock+0x92/0x100 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 process_backlog+0x3e2/0x7f0 net/core/dev.c:6485
 __napi_poll+0xc7/0x440 net/core/dev.c:7043
 napi_poll net/core/dev.c:7110 [inline]
 net_rx_action+0x617/0xda0 net/core/dev.c:7200
 handle_softirqs+0x3a7/0x930 kernel/softirq.c:558
 __do_softirq kernel/softirq.c:592 [inline]
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x157/0x240 kernel/softirq.c:641
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:653
 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:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4782
Code: 45 31 c9 68 c7 ba 59 81 e8 1c 12 09 00 48 83 c4 08 4c 89 ff e8 90 db fe ff 66 90 4c 89 ff e8 86 d1 ee 08 e8 31 48 2d 00 fb 5b <41> 5c 41 5d 41 5e 41 5f c3 44 89 f1 80 e1 07 80 c1 03 38 c1 7c 87
RSP: 0018:ffffc9000366f698 EFLAGS: 00000286
RAX: 19d4ac874b3ac100 RBX: ffff888074d6d974 RCX: ffffffff96a8ff03
RDX: dffffc0000000000 RSI: ffffffff8aab2b80 RDI: ffffffff8af9f000
RBP: ffffc9000366f710 R08: ffffffff81870508 R09: ffffed10171c765a
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff110171c760b R14: ffff8880b8e3b058 R15: ffff8880b8e3a300
 finish_task_switch+0x134/0x630 kernel/sched/core.c:4899
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12cc/0x45b0 kernel/sched/core.c:6373
 schedule+0x11b/0x1f0 kernel/sched/core.c:6456
 freezable_schedule include/linux/freezer.h:172 [inline]
 futex_wait_queue_me+0x25b/0x480 kernel/futex/core.c:2863
 futex_wait+0x2f8/0x740 kernel/futex/core.c:2964
 do_futex+0x1414/0x1810 kernel/futex/core.c:3982
 __do_sys_futex kernel/futex/core.c:4059 [inline]
 __se_sys_futex+0x407/0x490 kernel/futex/core.c:4040
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2b37465d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2b366de0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f2b37655fa8 RCX: 00007f2b37465d29
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2b37655fa8
RBP: 00007f2b37655fa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2b37655fac
R13: 0000000000000000 R14: 00007ffe12ea9760 R15: 00007ffe12ea9848
 </TASK>

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/02 00:57 linux-5.15.y 91786f140358 d3ccff63 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_futex
2025/01/01 17:38 linux-5.15.y 91786f140358 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_futex
2024/12/14 04:24 linux-5.15.y 0a51d2d4527b 7cbfbb3a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/11/13 09:14 linux-5.15.y 3c17fc483905 62026c85 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/10/12 08:25 linux-5.15.y 3a5928702e71 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/10/06 13:38 linux-5.15.y 3a5928702e71 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in sys_futex
2024/09/23 11:34 linux-5.15.y 3a5928702e71 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/08/13 03:25 linux-5.15.y 7e89efd3ae1c 7b0f4b46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/08/03 03:41 linux-5.15.y 7e89efd3ae1c 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/06/12 14:06 linux-5.15.y c61bd26ae81a f815599d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/06/05 16:49 linux-5.15.y c61bd26ae81a 5aa1a7c9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_futex
2024/08/22 15:56 linux-5.15.y fa93fa65db6e ca02180f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-arm64 INFO: rcu detected stall in sys_futex
* Struck through repros no longer work on HEAD.