[v5.15] INFO: rcu detected stall in sys_futex (2)

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Jun 5, 2024, 12:49:37 PMJun 5
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Hello,

syzbot found the following issue on:

HEAD commit: c61bd26ae81a Linux 5.15.160
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=115155f2980000
kernel config: https://syzkaller.appspot.com/x/.config?x=235f0e81ca937c17
dashboard link: https://syzkaller.appspot.com/bug?extid=6ceb9abf06f08ceec1d2
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d61a97eef8b9/disk-c61bd26a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/ab4908b4b59b/vmlinux-c61bd26a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d818fd46802b/bzImage-c61bd26a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6ceb9a...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (10499 ticks this GP) idle=513/1/0x4000000000000000 softirq=12148/12148 fqs=1
(t=10501 jiffies g=14017 q=2)
rcu: rcu_preempt kthread starved for 10500 jiffies! g14017 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:26712 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5417 Comm: syz-executor.2 Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:match_held_lock+0x1/0xb0 kernel/locking/lockdep.c:5070
Code: 03 00 75 cf 48 c7 c7 20 28 8b 8a 48 c7 c6 60 28 8b 8a e8 82 12 2e f7 0f 0b eb b6 e8 09 fb ff ff 66 0f 1f 84 00 00 00 00 00 55 <53> bd 01 00 00 00 48 39 77 10 74 67 48 89 fb 81 7f 20 00 00 10 00
RSP: 0018:ffffc90000dd0a70 EFLAGS: 00000087
RAX: 0000000000000003 RBX: ffff88807d930b40 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffff8880b9b3a358 RDI: ffff88807d930b40
RBP: ffffc90000dd0b58 R08: dffffc0000000000 R09: fffffbfff1bc8cce
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807d930b64
R13: 1ffff1100fb2615d R14: 0000000000000002 R15: ffff88807d930ae8
FS: 0000555556f3c480(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fc43000 CR3: 0000000063e3f000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<IRQ>
__lock_unpin_lock kernel/locking/lockdep.c:5436 [inline]
lock_unpin_lock+0x1d5/0x4d0 kernel/locking/lockdep.c:5723
rq_unpin_lock kernel/sched/sched.h:1562 [inline]
ttwu_do_wakeup+0x120/0x4d0 kernel/sched/core.c:3571
ttwu_queue kernel/sched/core.c:3823 [inline]
try_to_wake_up+0x795/0x1300 kernel/sched/core.c:4146
signal_wake_up_state kernel/signal.c:770 [inline]
signal_wake_up include/linux/sched/signal.h:421 [inline]
complete_signal+0x5a0/0x9a0 kernel/signal.c:1062
__send_signal+0xaaf/0xd40 kernel/signal.c:1182
do_send_sig_info kernel/signal.c:1294 [inline]
group_send_sig_info+0x260/0x2d0 kernel/signal.c:1442
do_bpf_send_signal+0x81/0x150 kernel/trace/bpf_trace.c:779
irq_work_single kernel/irq_work.c:155 [inline]
irq_work_run_list+0x20b/0x370 kernel/irq_work.c:177
irq_work_run+0x63/0xe0 kernel/irq_work.c:186
__sysvec_irq_work+0x9a/0x250 arch/x86/kernel/irq_work.c:22
sysvec_irq_work+0x89/0xb0 arch/x86/kernel/irq_work.c:17
</IRQ>
<TASK>
asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:664
RIP: 0010:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4785
Code: 45 31 c9 68 b7 90 59 81 e8 cc 1a 09 00 48 83 c4 08 4c 89 ff e8 60 da fe ff 66 90 4c 89 ff e8 f6 da cd 08 e8 d1 4b 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:ffffc90002fd7838 EFLAGS: 00000286
RAX: 93b734642303b100 RBX: ffff8880748b9df4 RCX: ffffffff913eff03
RDX: dffffc0000000000 RSI: ffffffff8a8b2980 RDI: ffffffff8ad8f6c0
RBP: ffffc90002fd78b0 R08: ffffffff8186dcf0 R09: ffffed1017367469
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff11017367613 R14: ffff8880b9b3b098 R15: ffff8880b9b3a340
finish_task_switch+0x134/0x630 kernel/sched/core.c:4902
context_switch kernel/sched/core.c:5033 [inline]
__schedule+0x12cc/0x45b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
irqentry_exit+0x53/0x80 kernel/entry/common.c:432
asm_sysvec_call_function_single+0x16/0x20 arch/x86/include/asm/idtentry.h:646
RIP: 0010:schedule+0x10a/0x1f0 kernel/sched/core.c:6458
Code: a3 f7 49 8b 07 4c 39 f8 74 0d 4c 89 f7 be 01 00 00 00 e8 89 d0 c6 f9 4c 89 eb 48 c1 eb 03 eb 0a 49 f7 45 00 08 00 00 00 74 39 <bf> 01 00 00 00 e8 7c 30 31 f7 31 ff e8 35 b9 ff ff bf 01 00 00 00
RSP: 0018:ffffc90002fd7c10 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 1ffff1100fb26000 RCX: ffffffff8a263012
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807d930000
RBP: ffffc90002fd7d30 R08: dffffc0000000000 R09: ffffed100fb26001
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff88807d930000 R14: 0000000000000000 R15: ffffc90002fd7d80
freezable_schedule include/linux/freezer.h:172 [inline]
do_nanosleep+0x1bc/0x7b0 kernel/time/hrtimer.c:2045
hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2098
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1313 [inline]
__se_sys_clock_nanosleep+0x323/0x3b0 kernel/time/posix-timers.c:1290
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: 0033:0x7f18bc997375
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007fffb3e52200 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 00007f18bcaa2f80 RCX: 00007f18bc997375
RDX: 00007fffb3e52240 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f18bcaa4980 R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000001a3da
R13: 00007f18bcaa312c R14: 0000000000000032 R15: 00007f18bcaa4980
</TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 5422 Comm: syz-executor.2 Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_dump_cpu_stacks+0x223/0x390 kernel/rcu/tree_stall.h:349
print_cpu_stall+0x320/0x600 kernel/rcu/tree_stall.h:633
check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
rcu_pending kernel/rcu/tree.c:3932 [inline]
rcu_sched_clock_irq+0x8d9/0x1150 kernel/rcu/tree.c:2619
update_process_times+0x196/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1686 [inline]
__hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1750
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
__sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:finish_lock_switch+0x91/0x100 kernel/sched/core.c:4785
Code: 45 31 c9 68 b7 90 59 81 e8 cc 1a 09 00 48 83 c4 08 4c 89 ff e8 60 da fe ff 66 90 4c 89 ff e8 f6 da cd 08 e8 d1 4b 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:ffffc900030d7698 EFLAGS: 00000286
RAX: 6ad0c8b1f3a5eb00 RBX: ffff888013bdd974 RCX: ffffffff913eff03
RDX: dffffc0000000000 RSI: ffffffff8a8b2980 RDI: ffffffff8ad8f6c0
RBP: ffffc900030d7710 R08: ffffffff8186dcf0 R09: ffffed1017347469
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: 1ffff11017347613 R14: ffff8880b9a3b098 R15: ffff8880b9a3a340
finish_task_switch+0x134/0x630 kernel/sched/core.c:4902
context_switch kernel/sched/core.c:5033 [inline]
__schedule+0x12cc/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
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: 0033:0x7f18bc96bf69
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:00007f18bb4c4178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f18bcaa3058 RCX: 00007f18bc96bf69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f18bcaa3058
RBP: 00007f18bcaa3050 R08: 00007f18bb4c46c0 R09: 00007f18bb4c46c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f18bcaa305c
R13: 000000000000006e R14: 00007fffb3e520a0 R15: 00007fffb3e52188
</TASK>
sched: RT throttling activated


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