syzbot


INFO: rcu detected stall in sys_futex

Status: upstream: reported on 2023/07/05 11:35
Reported-by: syzbot+97f2ac670e5e7a3b48e4@syzkaller.appspotmail.com
First crash: 583d, last: 30d
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 68 12h40m 228d 0/28 upstream: reported on 2024/06/24 16:48
upstream INFO: rcu detected stall in sys_futex (3) kernel 959 1857d 1906d 0/28 auto-closed as invalid on 2020/03/08 12:44
upstream INFO: rcu detected stall in sys_futex (2) kernel 6 2025d 2169d 0/28 auto-closed as invalid on 2019/10/25 14:11
upstream INFO: rcu detected stall in sys_futex (4) kernel 1 1106d 1106d 0/28 closed as invalid on 2022/02/08 10:00
linux-5.15 INFO: rcu detected stall in sys_futex (2) origin:lts-only syz error 12 37d 247d 0/3 upstream: reported syz repro on 2024/06/05 16:49
upstream INFO: rcu detected stall in sys_futex kernel 1 2231d 2231d 0/28 closed as invalid on 2018/12/31 04:10
linux-5.15 INFO: rcu detected stall in sys_futex 4 403d 577d 0/3 auto-obsoleted due to no activity on 2024/04/10 17:08
upstream INFO: rcu detected stall in sys_futex (5) kernel 12 837d 1082d 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 406d 641d 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=b66c/1/0x4000000000000000 softirq=37529/37531 fqs=4
	(detected by 1, t=10502 jiffies, g=49253, q=74 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10335 Comm: syz.0.1278 Not tainted 6.1.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:preempt_count_add+0xc6/0x180 kernel/sched/core.c:5714
Code: 00 65 48 8b 1d 7b e0 a3 7e 48 81 c3 d8 14 00 00 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 ae a1 83 00 4c 89 33 5b <41> 5e 41 5f c3 e8 40 ac e2 02 85 c0 74 9e 48 c7 c0 38 3c 9b 8e 48
RSP: 0018:ffffc90000007c28 EFLAGS: 00000006
RAX: 0000000000010004 RBX: 1ffff92000000f8c RCX: ffffffff97356103
RDX: 0000000000010000 RSI: ffffffff8b0dece0 RDI: 0000000000000001
RBP: ffffc90000007cd0 R08: ffffffff8179c8a2 R09: ffff888029ade340
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000046
R13: 1ffff92000000f88 R14: ffffffff9758bee0 R15: dffffc0000000000
FS:  00007f6fc30166c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3bc4e3 CR3: 00000000592cc000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:109 [inline]
 _raw_spin_lock_irqsave+0xb6/0x120 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x63/0x380 lib/debugobjects.c:753
 debug_hrtimer_deactivate kernel/time/hrtimer.c:426 [inline]
 debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:482
 __run_hrtimer kernel/time/hrtimer.c:1657 [inline]
 __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1753
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd4/0x130 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 a2 60 25 f7 f6 44 24 21 02 75 4e 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 17 c0 a1 f6 65 8b 05 b8 9f 45 75 85 c0 74 3f 48 c7 04 24 0e 36
RSP: 0018:ffffc900042d7a20 EFLAGS: 00000206
RAX: be1199ad84e21d00 RBX: 1ffff9200085af48 RCX: ffffffff97356103
RDX: dffffc0000000000 RSI: ffffffff8b0c0340 RDI: 0000000000000001
RBP: ffffc900042d7ab0 R08: dffffc0000000000 R09: ffffed100ee068b1
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff9200085af44 R14: ffffc900042d7a40 R15: 0000000000000246
 try_to_wake_up+0x7dd/0x12e0 kernel/sched/core.c:4226
 wake_up_process kernel/sched/core.c:4358 [inline]
 wake_up_q+0x8b/0xd0 kernel/sched/core.c:1006
 futex_wake+0x4ea/0x590 kernel/futex/waitwake.c:184
 do_futex+0x375/0x490 kernel/futex/syscalls.c:111
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex+0x3d7/0x460 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6fc2185d29
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:00007f6fc30160e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f6fc2376168 RCX: 00007f6fc2185d29
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6fc237616c
RBP: 00007f6fc2376160 R08: 0000000000000010 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f6fc237616c
R13: 0000000000000000 R14: 00007ffda2e925d0 R15: 00007ffda2e926b8
 </TASK>
rcu: rcu_preempt kthread starved for 10480 jiffies! g49253 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:26048 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 10337 Comm: syz.6.1271 Not tainted 6.1.123-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1fae/0x3460 kernel/smp.c:998
Code: 2f 44 89 ee 83 e6 01 31 ff e8 0e 44 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 99 40 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff
RSP: 0018:ffffc90003e87160 EFLAGS: 00000246
RAX: ffffffff817f5b89 RBX: 1ffff110171c8595 RCX: 0000000000080000
RDX: ffffc9000ccb2000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc90003e87540 R08: ffffffff817f5b52 R09: fffffbfff2249e4d
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8e42ca8
FS:  00007fb02cdfd6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000029bfb000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1334 [inline]
 text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534
 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:207
 static_key_enable+0x16/0x20 kernel/jump_label.c:220
 __sched_core_enable kernel/sched/core.c:376 [inline]
 sched_core_get+0xa6/0x1d0 kernel/sched/core.c:400
 sched_core_alloc_cookie+0x71/0xa0 kernel/sched/core_sched.c:18
 sched_core_share_pid+0x353/0x770 kernel/sched/core_sched.c:185
 __do_sys_prctl kernel/sys.c:2649 [inline]
 __se_sys_prctl+0x2a5/0x2d40 kernel/sys.c:2377
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb02bf85d29
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:00007fb02cdfd038 EFLAGS: 00000246 ORIG_RAX: 000000000000009d
RAX: ffffffffffffffda RBX: 00007fb02c175fa0 RCX: 00007fb02bf85d29
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 000000000000003e
RBP: 00007fb02c001b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb02c175fa0 R15: 00007ffc897ae058
 </TASK>

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/08 10:23 linux-6.1.y 7dc732d24ff7 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/10/14 09:18 linux-6.1.y aa4cd140bba5 084d8178 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_futex
2024/10/01 18:17 linux-6.1.y aa4cd140bba5 ea2b66a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_futex
2024/09/02 03:20 linux-6.1.y 311d8503ef9f 1eda0d14 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_futex
2024/08/05 06:08 linux-6.1.y 48d525b0e463 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_futex
2024/06/19 18:49 linux-6.1.y eb44d83053d6 41b7e219 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/11 01:38 linux-6.1.y 88690811da69 048c640a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/08 12:33 linux-6.1.y 88690811da69 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/07 10:14 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/06/06 13:57 linux-6.1.y 88690811da69 121701b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/05/09 12:07 linux-6.1.y 909ba1f1b414 05079661 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/05/05 09:10 linux-6.1.y 909ba1f1b414 610f2a54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_futex
2024/03/28 15:11 linux-6.1.y e5cd595e23c1 e91187ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2024/01/09 19:35 linux-6.1.y 38fb82ecd144 4807fb37 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2023/10/04 13:29 linux-6.1.y d23900f974e0 b7d7ff54 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2023/07/14 08:34 linux-6.1.y 61fd484b2cf6 d624500f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
2023/07/05 11:34 linux-6.1.y 0f4ac6b4c5f0 80298b6f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_futex
* Struck through repros no longer work on HEAD.