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

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Jun 10, 2024, 6:16:24 PM (11 days ago) Jun 10
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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=165b3d8c980000
kernel config: https://syzkaller.appspot.com/x/.config?x=235f0e81ca937c17
dashboard link: https://syzkaller.appspot.com/bug?extid=a8b639ddec1e095f1806
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+a8b639...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10524 ticks this GP) idle=159/1/0x4000000000000000 softirq=5895/5898 fqs=5
(t=10501 jiffies g=5377 q=75)
rcu: rcu_preempt kthread starved for 10492 jiffies! g5377 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27000 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 3726 Comm: syz-executor.3 Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:check_preemption_disabled+0x59/0x110 lib/smp_processor_id.c:19
Code: 48 8b 04 25 28 00 00 00 48 3b 44 24 08 0f 85 c7 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 48 c7 04 24 00 00 00 00 9c <8f> 04 24 f7 04 24 00 02 00 00 74 c9 49 89 f6 49 89 ff 65 4c 8b 25
RSP: 0018:ffffc90002ed7d00 EFLAGS: 00000046
RAX: 0000000080000000 RBX: 0000000000000000 RCX: ffffc90002ed7d03
RDX: 0000000000000000 RSI: ffffffff8a8b3c20 RDI: ffffffff8ad8f6c0
RBP: ffffc90002ed7e68 R08: dffffc0000000000 R09: fffffbfff1bc8cce
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920005dafb4
R13: 0000000000000046 R14: ffffc90002ed7dd0 R15: dffffc0000000000
FS: 00007fb73e32b6c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b3012d000 CR3: 000000005d4eb000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
lock_release+0x5c1/0x9a0 kernel/locking/lockdep.c:5645
do_write_seqcount_end include/linux/seqlock.h:565 [inline]
vtime_user_exit+0x2d1/0x400 kernel/sched/cputime.c:726
__context_tracking_exit+0x4c/0x80 kernel/context_tracking.c:160
user_exit_irqoff include/linux/context_tracking.h:47 [inline]
__enter_from_user_mode kernel/entry/common.c:22 [inline]
syscall_enter_from_user_mode+0x1bf/0x240 kernel/entry/common.c:110
do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb73f7d2f69
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:00007fb73e32b178 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fb73f90a058 RCX: 00007fb73f7d2f69
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb73f90a058
RBP: 00007fb73f90a050 R08: 00007fb73e32b6c0 R09: 00007fb73e32b6c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb73f90a05c
R13: 000000000000006e R14: 00007fffcdc71a30 R15: 00007fffcdc71b18
</TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 263 Comm: kworker/1:1H Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: 0x0 (kblockd)
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:ffffc900025a79b8 EFLAGS: 00000282
RAX: b80d8906e1939900 RBX: ffff88801e1b5974 RCX: ffffffff913eff03
RDX: dffffc0000000000 RSI: ffffffff8a8b2980 RDI: ffffffff8ad8f6c0
RBP: ffffc900025a7a30 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_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:207 [inline]
RIP: 0010:test_bit include/asm-generic/bitops/instrumented-non-atomic.h:135 [inline]
RIP: 0010:test_ti_thread_flag include/linux/thread_info.h:118 [inline]
RIP: 0010:need_resched include/linux/sched.h:2113 [inline]
RIP: 0010:schedule+0x137/0x1f0 kernel/sched/core.c:6461
Code: 00 00 e8 7c 30 31 f7 31 ff e8 35 b9 ff ff bf 01 00 00 00 e8 eb 31 31 f7 4c 89 ef be 08 00 00 00 e8 4e fc a3 f7 42 80 3c 23 00 <74> c7 4c 89 ef e8 af fa a3 f7 eb bd 4d 89 ee 49 83 c6 2c 4c 89 f0
RSP: 0018:ffffc900025a7da8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff110031dfb28 RCX: ffffffff8a263012
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888018efd940
RBP: dffffc0000000000 R08: dffffc0000000000 R09: ffffed10031dfb29
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff888018efd940 R14: 0000000000000000 R15: ffff8880b9b39f40
worker_thread+0xf56/0x1280 kernel/workqueue.c:2478
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>


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