Re: [syzbot] [mm?] WARNING in copy_process

[syzbot <syzbot+69c74d38464686431506@syzkaller.appspotmail.com>]

syzbot has found a reproducer for the following issue on:

HEAD commit:    7fa4d8dc380f Add linux-next specific files for 20250821
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=1036def0580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=ae76068823a236b3
dashboard link: https://syzkaller.appspot.com/bug?extid=69c74d38464686431506
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13595c62580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63178c6ef3f8/disk-7fa4d8dc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/c5c27b0841e0/vmlinux-7fa4d8dc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/9a8832715cca/bzImage-7fa4d8dc.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+69c74d38464686431506@syzkaller.appspotmail.com

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pvqspinlock: lock 0xffff8881c5419bc0 has corrupted value 0x0!
WARNING: kernel/locking/qspinlock_paravirt.h:506 at __pv_queued_spin_unlock_slowpath+0x1fe/0x2a0 kernel/locking/qspinlock_paravirt.h:504, CPU#1: syz.6.106/8286
Modules linked in:
CPU: 1 UID: 0 PID: 8286 Comm: syz.6.106 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__pv_queued_spin_unlock_slowpath+0x1fe/0x2a0 kernel/locking/qspinlock_paravirt.h:504
Code: f8 a8 9b f6 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 93 00 00 00 8b 13 48 c7 c7 00 0c ab 8b 48 89 de e8 73 9c fb f5 90 <0f> 0b 90 90 eb 95 48 c7 c7 90 e4 40 8e 4c 89 f6 4c 89 fa e8 fa c5
RSP: 0018:ffffc900100c78c0 EFLAGS: 00010246
RAX: 9e0501aa69750800 RBX: ffff8881c5419bc0 RCX: ffff8881921f9e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 1ffff11038a83379 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff1c7a604 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff8881c5419bd0 R15: ffff8881c5419bc8
FS:  0000555565514500(0000) GS:ffff8881258c4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8801a12e9c CR3: 00000001d6f0c000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __raw_callee_save___pv_queued_spin_unlock_slowpath+0x15/0x30
 .slowpath+0x9/0x18
 pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:562 [inline]
 queued_spin_unlock arch/x86/include/asm/qspinlock.h:57 [inline]
 do_raw_spin_unlock+0x122/0x240 kernel/locking/spinlock_debug.c:142
 __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_unlock+0x1e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 copy_process+0x2793/0x3c00 kernel/fork.c:2435
 kernel_clone+0x21e/0x840 kernel/fork.c:2608
 __do_sys_clone3 kernel/fork.c:2912 [inline]
 __se_sys_clone3+0x256/0x2d0 kernel/fork.c:2891
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb44b1c3449
Code: d7 08 00 48 8d 3d fc d7 08 00 e8 12 29 f6 ff 66 90 b8 ea ff ff ff 48 85 ff 74 2c 48 85 d2 74 27 49 89 c8 b8 b3 01 00 00 0f 05 <48> 85 c0 7c 18 74 01 c3 31 ed 48 83 e4 f0 4c 89 c7 ff d2 48 89 c7
RSP: 002b:00007ffc514a7578 EFLAGS: 00000206 ORIG_RAX: 00000000000001b3
RAX: ffffffffffffffda RBX: 00007fb44b145860 RCX: 00007fb44b1c3449
RDX: 00007fb44b145860 RSI: 0000000000000058 RDI: 00007ffc514a75c0
RBP: 00007fb44a7fe6c0 R08: 00007fb44a7fe6c0 R09: 00007ffc514a76a7
R10: 0000000000000008 R11: 0000000000000206 R12: ffffffffffffffa8
R13: 000000000000000b R14: 00007ffc514a75c0 R15: 00007ffc514a76a8
 </TASK>


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