[v6.1] INFO: rcu detected stall in sys_nanosleep

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May 10, 2024, 12:21:29 AMMay 10
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Hello,

syzbot found the following issue on:

HEAD commit: 909ba1f1b414 Linux 6.1.90
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16fd5e04980000
kernel config: https://syzkaller.appspot.com/x/.config?x=3be6d6f79b879a67
dashboard link: https://syzkaller.appspot.com/bug?extid=8f259edf7a735de05f1e
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/63178de7cba7/disk-909ba1f1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/25dec90d8126/vmlinux-909ba1f1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/25509ea1c6cd/bzImage-909ba1f1.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8f259e...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
(detected by 1, t=10502 jiffies, g=13733, q=42 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10501 (4294958652-4294948151), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g13733 f0x2 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:26136 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: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:308
</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: 3542 Comm: syz-fuzzer Not tainted 6.1.90-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:check_preemption_disabled+0x42/0x110 lib/smp_processor_id.c:55
Code: 08 65 8b 1d 10 49 77 75 65 8b 05 b1 9e 77 75 a9 ff ff ff 7f 74 22 65 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
RSP: 0018:ffffc90003a7f608 EFLAGS: 00000046
RAX: 3cd833ad6f171900 RBX: 0000000000000000 RCX: ffffc90003a7f603
RDX: 0000000000000001 RSI: ffffffff8aec1340 RDI: ffffffff8b3d43e0
RBP: ffffc90003a7f778 R08: dffffc0000000000 R09: fffffbfff1ce7046
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200074fed4
R13: 0000000000000046 R14: ffffc90003a7f6d0 R15: dffffc0000000000
FS: 000000c00005a090(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32129000 CR3: 000000001f3db000 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:467 [inline]
lock_release+0x5cb/0xa20 kernel/locking/lockdep.c:5684
do_write_seqcount_end include/linux/seqlock.h:561 [inline]
psi_group_change+0xace/0x12d0 kernel/sched/psi.c:876
psi_task_switch+0x195/0x770 kernel/sched/psi.c:950
psi_sched_switch kernel/sched/stats.h:199 [inline]
__schedule+0x2056/0x4550 kernel/sched/core.c:6553
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
irqentry_exit+0x53/0x80 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:preempt_count_add+0x2/0x180 kernel/sched/core.c:5698
Code: 0c 24 80 e1 07 80 c1 03 38 c1 7c 97 48 8b 3c 24 e8 43 b2 83 00 eb 8c e9 f2 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 <41> 56 53 89 fb 48 c7 c0 60 31 c9 91 48 c1 e8 03 49 bf 00 00 00 00
RSP: 0018:ffffc90003a7fc08 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 1ffff1100fd43b28 RCX: ffffffff8a933926
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 0000000000000001
RBP: ffffc90003a7fd30 R08: dffffc0000000000 R09: ffffed100fd43b29
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807ea1d940
R13: ffffc90003a7fdc0 R14: ffff88807ea1ebb8 R15: dffffc0000000000
schedule+0xb8/0x180 kernel/sched/core.c:6633
do_nanosleep+0x192/0x5f0 kernel/time/hrtimer.c:2045
hrtimer_nanosleep+0x24d/0x490 kernel/time/hrtimer.c:2098
__do_sys_nanosleep kernel/time/hrtimer.c:2133 [inline]
__se_sys_nanosleep kernel/time/hrtimer.c:2119 [inline]
__x64_sys_nanosleep+0x265/0x2c0 kernel/time/hrtimer.c:2119
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: 0033:0x472f57
Code: 8b 44 24 20 b9 40 42 0f 00 f7 f1 48 89 04 24 b8 e8 03 00 00 f7 e2 48 89 44 24 08 48 89 e7 be 00 00 00 00 b8 23 00 00 00 0f 05 <48> 83 c4 10 5d c3 cc cc cc b8 ba 00 00 00 0f 05 89 44 24 08 c3 cc
RSP: 002b:000000c00006bf18 EFLAGS: 00000202 ORIG_RAX: 0000000000000023
RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 0000000000472f57
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000c00006bf18
RBP: 000000c00006bf28 R08: 00007ffdacd820b0 R09: 0000000000000010
R10: 00007ffdacd82080 R11: 0000000000000202 R12: 000000c00006bf18
R13: 000000c00102f400 R14: 000000c0000064e0 R15: 0000000000000001
</TASK>


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