linux-kernel - [syzbot] [kvm-x86?] WARNING in kvm_arch_can_dequeue_async_page

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Message-ID: <690e0be4.a70a0220.22f260.0050.GAE@google.com>
Date: Fri, 07 Nov 2025 07:10:28 -0800
From: syzbot <syzbot+6bea72f0c8acbde47c55@...kaller.appspotmail.com>
To: bp@...en8.de, dave.hansen@...ux.intel.com, hpa@...or.com, 
	kvm@...r.kernel.org, linux-kernel@...r.kernel.org, mingo@...hat.com, 
	pbonzini@...hat.com, seanjc@...gle.com, syzkaller-bugs@...glegroups.com, 
	tglx@...utronix.de, x86@...nel.org
Subject: [syzbot] [kvm-x86?] WARNING in kvm_arch_can_dequeue_async_page_present

Hello,

syzbot found the following issue on:

HEAD commit:    9c0826a5d9aa Add linux-next specific files for 20251107
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13a67012580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4f8fcc6438a785e7
dashboard link: https://syzkaller.appspot.com/bug?extid=6bea72f0c8acbde47c55
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=14e110b4580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14ab1114580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/6b76dc0ec17f/disk-9c0826a5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/522b6d2a1d1d/vmlinux-9c0826a5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/4a58225d70f3/bzImage-9c0826a5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6bea72f0c8acbde47c55@...kaller.appspotmail.com

kvm_intel: L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
------------[ cut here ]------------
WARNING: arch/x86/kvm/x86.c:13965 at kvm_arch_can_dequeue_async_page_present+0x1a9/0x2f0 arch/x86/kvm/x86.c:13965, CPU#0: syz.0.17/5998
Modules linked in:
CPU: 0 UID: 0 PID: 5998 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:kvm_arch_can_dequeue_async_page_present+0x1a9/0x2f0 arch/x86/kvm/x86.c:13965
Code: 00 65 48 8b 0d 58 81 72 11 48 3b 4c 24 40 75 21 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d e9 3e af 20 0a cc e8 48 e1 79 00 90 <0f> 0b 90 b0 01 eb c0 e8 4b c1 1d 0a f3 0f 1e fa 4c 8d b3 f8 02 00
RSP: 0018:ffffc90003167460 EFLAGS: 00010293
RAX: ffffffff8147eee8 RBX: ffff888030280000 RCX: ffff88807fda1e80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
RBP: ffffc900031674e8 R08: ffff88803028003f R09: 1ffff11006050007
R10: dffffc0000000000 R11: ffffed1006050008 R12: 1ffff9200062ce8c
R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000
FS:  000055556a8c3500(0000) GS:ffff888125a79000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000072cc2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kvm_check_async_pf_completion+0x102/0x3c0 virt/kvm/async_pf.c:158
 vcpu_enter_guest arch/x86/kvm/x86.c:11209 [inline]
 vcpu_run+0x26be/0x7760 arch/x86/kvm/x86.c:11650
 kvm_arch_vcpu_ioctl_run+0x116c/0x1cb0 arch/x86/kvm/x86.c:11995
 kvm_vcpu_ioctl+0x99a/0xed0 virt/kvm/kvm_main.c:4477
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 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: 0033:0x7f1588b8f6c9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdfcd816a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f1588de5fa0 RCX: 00007f1588b8f6c9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00007f1588c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1588de5fa0 R14: 00007f1588de5fa0 R15: 0000000000000003
 </TASK>


---
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