[syzbot] [kvm?] WARNING in kvm_put_kvm (3)

[syzbot] [kvm?] WARNING in kvm_put_kvm (3)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    6b8c8af514d7 Add linux-next specific files for 20260807
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14548079580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=6d343b54cc50df0f
dashboard link: https://syzkaller.appspot.com/bug?extid=d4faf7db59e11f6fd1ab
compiler:       Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1528e132580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/71ff4edcb608/disk-6b8c8af5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1f5fa331d8f2/vmlinux-6b8c8af5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/f993558ec63b/bzImage-6b8c8af5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d4faf7db59e11f6fd1ab@syzkaller.appspotmail.com

------------[ cut here ]------------
timer_delete_sync(&sdp->delay_work)
WARNING: kernel/rcu/srcutree.c:706 at cleanup_srcu_struct+0x3aa/0x890 kernel/rcu/srcutree.c:706, CPU#1: syz.1.1070/8126
Modules linked in:
CPU: 1 UID: 0 PID: 8126 Comm: syz.1.1070 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:cleanup_srcu_struct+0x3aa/0x890 kernel/rcu/srcutree.c:706
Code: b9 8a 00 48 83 7d 00 00 4c 8b 74 24 10 0f 85 dd 03 00 00 41 ff c5 41 83 e5 0f 41 83 fd 07 0f 86 0e ff ff ff e9 ab 00 00 00 90 <0f> 0b 90 4c 8d b5 00 02 00 00 4c 89 f3 48 c1 eb 03 48 b8 00 00 00
RSP: 0018:ffffc9000bbbfc50 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000607edad41c80 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8e253559 RDI: 00000000ffffffff
RBP: ffffe8ffffc4dc80 R08: ffffffff9058fb7f R09: 1ffffffff20b1f6f
R10: dffffc0000000000 R11: fffffbfff20b1f70 R12: ffff88807bfa8000
R13: 0000000000000000 R14: ffffffff8e5237d0 R15: 1ffffffff1ca47de
FS:  000055557293c500(0000) GS:ffff88812500c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000071042000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 kvm_destroy_vm virt/kvm/kvm_main.c:1303 [inline]
 kvm_put_kvm+0x9cb/0xb50 virt/kvm/kvm_main.c:1332
 kvm_vm_release+0x43/0x50 virt/kvm/kvm_main.c:1355
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x22e/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x328/0x510 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f25cc99e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffed2b09948 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffed2b09a30 RCX: 00007f25cc99e0d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000051665 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2d520000 R11: 0000000000000246 R12: 00007ffed2b09a70
R13: 00007f25ccc25fac R14: 00000000000516bf R15: 00007f25ccc25fa0
 </TASK>


---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
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If you want syzbot to run the reproducer, reply with:
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Forwarded: test for d4faf7db59e11f6fd1ab

[syzbot]

For archival purposes, forwarding an incoming command email to
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***

Subject: test for d4faf7db59e11f6fd1ab
Author: shpark061104@gmail.com

#syz test: git://git.kernel.org/pub/scm/virt/kvm/kvm.git master

Forwarded: test patch for d4faf7db59e11f6fd1ab

[syzbot]

For archival purposes, forwarding an incoming command email to
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***

Subject: test patch for d4faf7db59e11f6fd1ab
Author: shpark061104@gmail.com

#syz test: git://git.kernel.org/pub/scm/virt/kvm/kvm.git master

--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1297,6 +1297,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
                kvm_free_memslots(kvm, &kvm->__memslots[i][0]);
                kvm_free_memslots(kvm, &kvm->__memslots[i][1]);
        }
+        srcu_barrier(&kvm->irq_srcu);
        cleanup_srcu_struct(&kvm->irq_srcu);
        srcu_barrier(&kvm->srcu);
        cleanup_srcu_struct(&kvm->srcu);

Forwarded: test for d4faf7db59e11f6fd1ab

[syzbot]

For archival purposes, forwarding an incoming command email to
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com.

***

Subject: test for d4faf7db59e11f6fd1ab
Author: shpark061104@gmail.com

#syz test: git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
master

# https://syzkaller.appspot.com/bug?id=928e57747811470fbf24307d324a86e066ac2fe2
# See https://goo.gl/kgGztJ for information about syzkaller reproducers.
#{"repeat":true,"procs":5,"slowdown":1,"sandbox":"none","sandbox_arg":0,"tun":true,"netdev":true,"resetnet":true,"cgroups":true,"binfmt_misc":true,"close_fds":true,"usb":true,"vhci":true,"wifi":true,"ieee802154":true,"sysctl":true,"swap":true,"tmpdir":true,"segv":true,"callcomments":true}
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)
mprotect(&(0x7f0000000000/0xf000)=nil, 0xf000, 0x1)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
ioctl$KVM_CREATE_IRQCHIP(r1, 0xae60)
ioctl$KVM_REGISTER_COALESCED_MMIO(r1, 0x4010ae67,
&(0x7f0000000040)={0xffff1000, 0x100000, 0xfffffffd})