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: 302d, last: 35d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_futex (3) kernel 959 1576d 1625d 0/26 auto-closed as invalid on 2020/03/08 12:44
upstream INFO: rcu detected stall in sys_futex (2) kernel 6 1744d 1889d 0/26 auto-closed as invalid on 2019/10/25 14:11
upstream INFO: rcu detected stall in sys_futex (4) kernel 1 826d 826d 0/26 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in sys_futex kernel 1 1950d 1950d 0/26 closed as invalid on 2018/12/31 04:10
linux-5.15 INFO: rcu detected stall in sys_futex 4 122d 297d 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 556d 801d 0/26 auto-obsoleted due to no activity on 2023/02/12 18:33
upstream INFO: rcu detected stall in sys_futex (6) kernel 10 125d 360d 0/26 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: 	1-...!: (0 ticks this GP) idle=2c44/1/0x4000000000000000 softirq=20175/20175 fqs=25
	(detected by 0, t=10502 jiffies, g=27885, q=548 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7500 Comm: syz-executor.1 Not tainted 6.1.83-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:validate_chain+0xc0/0x5950 kernel/locking/lockdep.c:3792
Code: 4a 89 44 21 17 48 b8 f2 f2 f2 f2 f2 00 f3 f3 4a 89 44 21 23 48 89 8c 24 a0 00 00 00 42 c6 44 21 2b f3 48 89 b4 24 b0 00 00 00 <4c> 8d 6e 20 4c 89 e8 48 c1 e8 03 48 89 44 24 68 42 0f b6 04 20 84
RSP: 0018:ffffc900001e07c0 EFLAGS: 00000806
RAX: f3f300f2f2f2f2f2 RBX: ffffffff9018f260 RCX: 1ffff9200003c118
RDX: 0000000000000001 RSI: ffff8880570028a0 RDI: ffff888057001dc0
RBP: ffffc900001e0a70 R08: dffffc0000000000 R09: fffffbfff2092e45
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888057001dc0 R14: da2e616334457c0f R15: 1ffff1100ae00518
FS:  0000555556733480(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f30cd1ad988 CR3: 0000000028ec7000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 rcu_read_lock include/linux/rcupdate.h:791 [inline]
 advance_sched+0x6ec/0x970 net/sched/sch_taprio.c:753
 __run_hrtimer kernel/time/hrtimer.c:1686 [inline]
 __hrtimer_run_queues+0x5e5/0xe50 kernel/time/hrtimer.c:1750
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124
Code: 37 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 2b 10 35 09 e8 06 2c 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28
RSP: 0018:ffffc900140af8a8 EFLAGS: 00000286
RAX: 232b4ffb83f52200 RBX: ffff888057873bb4 RCX: ffffffff91c8f103
RDX: dffffc0000000000 RSI: ffffffff8aebee40 RDI: ffff8880570033b8
RBP: ffffc900140af8f0 R08: dffffc0000000000 R09: ffffed1017327541
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888057001dc0
R13: 1ffff110173276eb R14: ffff8880b993aa00 R15: ffff8880b993b758
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1435/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 futex_wait_queue+0x149/0x1d0 kernel/futex/waitwake.c:355
 futex_wait+0x203/0x5c0 kernel/futex/waitwake.c:656
 do_futex+0x3b5/0x490 kernel/futex/syscalls.c:106
 __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+0x3d/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f18a347dda9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc2810c968 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 000000000002b8c8 RCX: 00007f18a347dda9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f18a35abf8c
RBP: 0000000000000032 R08: 00007f18a35abf8c R09: 00007f18a35abf8c
R10: 00007ffc2810caa0 R11: 0000000000000246 R12: 00007f18a35abf8c
R13: 000000000002b8fa R14: 00007ffc2810cac0 R15: 00007ffc2810caa0
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10451 jiffies! g27885 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=13706
rcu: rcu_preempt kthread starved for 10452 jiffies! g27885 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
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:I stack:26680 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935
 rcu_gp_fqs_loop+0x2d2/0x1120 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 7503 Comm: syz-executor.2 Not tainted 6.1.83-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1fb0/0x3460 kernel/smp.c:998
Code: 2f 44 89 ee 83 e6 01 31 ff e8 ec 42 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 77 3f 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:ffffc900038a76c0 EFLAGS: 00000293
RAX: ffffffff817f459b RBX: 1ffff110173281b1 RCX: ffff88805e69bb80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900038a7aa0 R08: ffffffff817f4564 R09: fffffbfff2092e45
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b9940d88
FS:  0000555556d8a480(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32226000 CR3: 0000000054973000 CR4: 00000000003506f0
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_disable_cpuslocked+0xca/0x1b0 kernel/jump_label.c:207
 static_key_disable+0x16/0x20 kernel/jump_label.c:215
 tracepoint_remove_func kernel/tracepoint.c:417 [inline]
 tracepoint_probe_unregister+0x6e6/0x980 kernel/tracepoint.c:551
 bpf_raw_tp_link_release+0x5f/0x80 kernel/bpf/syscall.c:3175
 bpf_link_free kernel/bpf/syscall.c:2749 [inline]
 bpf_link_put+0x234/0x2c0 kernel/bpf/syscall.c:2775
 bpf_link_release+0x37/0x40 kernel/bpf/syscall.c:2784
 __fput+0x3b7/0x890 fs/file_table.c:320
 task_work_run+0x246/0x300 kernel/task_work.c:179
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:297
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f052687cc9a
Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24
RSP: 002b:00007ffca8b8d7c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007f052687cc9a
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 00007f05269ad980 R08: 0000001b32820000 R09: 000000000000014b
R10: 000000008a7ed88d R11: 0000000000000293 R12: 000000000002bbf0
R13: ffffffffffffffff R14: 00007f0526400000 R15: 000000000002b8af
 </TASK>
vkms_vblank_simulate: vblank timer overrun

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
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.