[v5.15] INFO: rcu detected stall in sys_wait4

[syzbot]

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=11b5406c980000
kernel config: https://syzkaller.appspot.com/x/.config?x=235f0e81ca937c17
dashboard link: https://syzkaller.appspot.com/bug?extid=265140eadd9f3764930f
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+265140...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...0: (1 GPs behind) idle=f43/1/0x4000000000000000 softirq=18315/18316 fqs=5246
(detected by 0, t=10502 jiffies, g=23181, q=714)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3530 Comm: syz-executor.0 Not tainted 5.15.160-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x4/0x60 kernel/kcov.c:196
Code: 00 00 00 0f 1f 00 53 48 89 fb e8 17 00 00 00 48 8b 3d e8 0b 64 0c 48 89 de 5b e9 f7 f6 48 00 cc cc cc cc cc cc cc 48 8b 04 24 <65> 48 8b 0d f4 12 82 7e 65 8b 15 f5 12 82 7e f7 c2 00 01 ff 00 74
RSP: 0018:ffffc90000dd0d20 EFLAGS: 00000097
RAX: ffffffff816f906b RBX: 0000000000000000 RCX: ffff88807327d940
RDX: ffff88807327d940 RSI: 0000000000000001 RDI: 0000000000000007
RBP: 0000000000000001 R08: ffffffff816f905d R09: fffffbfff22b917f
R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8880b9b2a300 R14: ffff88807b463b40 R15: dffffc0000000000
FS: 0000555556778480(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2fc21000 CR3: 0000000064115000 CR4: 00000000003506e0
Call Trace:
<NMI>
</NMI>
<IRQ>
cpu_max_bits_warn include/linux/cpumask.h:108 [inline]
cpumask_check include/linux/cpumask.h:115 [inline]
cpumask_test_cpu include/linux/cpumask.h:344 [inline]
cpu_online include/linux/cpumask.h:895 [inline]
trace_hrtimer_start include/trace/events/timer.h:199 [inline]
debug_activate kernel/time/hrtimer.c:476 [inline]
enqueue_hrtimer+0x5b/0x390 kernel/time/hrtimer.c:1084
__run_hrtimer kernel/time/hrtimer.c:1703 [inline]
__hrtimer_run_queues+0x6b6/0xcf0 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:call_rcu+0x7aa/0xa70 kernel/rcu/tree.c:3088
Code: 3c 03 00 74 08 4c 89 f7 e8 53 f2 5e 00 f6 84 24 81 00 00 00 02 75 59 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <48> b8 00 00 00 00 00 fc ff df 4a c7 04 28 00 00 00 00 66 42 c7 44
RSP: 0018:ffffc90002df7480 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff920005beea0 RCX: ffffffff913eff03
RDX: dffffc0000000000 RSI: ffffffff8a8b2980 RDI: ffffffff8ad8f6c0
RBP: ffffc90002df75a0 R08: ffffffff8186dcf0 R09: fffffbfff1bc8cce
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff11017367654
R13: 1ffff920005bee9c R14: ffffc90002df7500 R15: 0000000000000246
__dentry_kill+0x436/0x650 fs/dcache.c:582
shrink_dentry_list+0x398/0x6a0 fs/dcache.c:1177
shrink_dcache_parent+0xc9/0x480
d_invalidate+0x118/0x2d0 fs/dcache.c:1713
proc_invalidate_siblings_dcache+0x3c2/0x660 fs/proc/inode.c:150
release_task+0x15d1/0x1750 kernel/exit.c:269
wait_task_zombie kernel/exit.c:1179 [inline]
wait_consider_task+0x1994/0x2e50 kernel/exit.c:1406
do_wait_thread kernel/exit.c:1469 [inline]
do_wait+0x30c/0xaf0 kernel/exit.c:1586
kernel_wait4+0x29e/0x3e0 kernel/exit.c:1749
__do_sys_wait4 kernel/exit.c:1777 [inline]
__se_sys_wait4 kernel/exit.c:1773 [inline]
__x64_sys_wait4+0x130/0x1e0 kernel/exit.c:1773
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: 0033:0x7f1da31098d7
Code: 89 7c 24 10 48 89 4c 24 18 e8 d5 a3 02 00 4c 8b 54 24 18 8b 54 24 14 41 89 c0 48 8b 74 24 08 8b 7c 24 10 b8 3d 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 89 44 24 10 e8 25 a4 02 00 8b 44
RSP: 002b:00007ffc20a24740 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000000000000021d RCX: 00007f1da31098d7
RDX: 0000000040000001 RSI: 00007ffc20a247bc RDI: 00000000ffffffff
RBP: 00007ffc20a247bc R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000032
R13: 0000000000029fa2 R14: 0000000000029b49 R15: 0000000000000006
</TASK>


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