* [moderation/CI] Re: KVM: x86: Document and enforce APIC base memory hole
@ 2026-07-06 15:08 syzbot ci
2026-07-06 15:19 ` Aleksandr Nogikh
0 siblings, 1 reply; 2+ messages in thread
From: syzbot ci @ 2026-07-06 15:08 UTC (permalink / raw)
To: syzkaller-upstream-moderation; +Cc: syzbot
syzbot ci has tested the following series
[v1] KVM: x86: Document and enforce APIC base memory hole
https://lore.kernel.org/all/20260706092021.3625908-2-twiederh@redhat.com
* [PATCH 1/4] KVM: x86: Document that KVM_CREATE_IRQCHIP must precede vcpu creation
* [PATCH 2/4] KVM: x86: Document APIC base address constraint for in-kernel irqchip
* [PATCH 3/4] KVM: x86: Reject KVM_CREATE_IRQCHIP if APIC base is already mapped
* [PATCH 4/4] KVM: x86: Reject user memory regions covering the APIC base
and found the following issue:
WARNING: suspicious RCU usage in gfn_to_memslot
Full report is available here:
https://ci.syzbot.org/series/b02ae7eb-bae2-492f-88f2-fa1b511c93cf
***
WARNING: suspicious RCU usage in gfn_to_memslot
tree: kvm-next
URL: https://kernel.googlesource.com/pub/scm/virt/kvm/kvm/
base: 8cd9520d35a6c38db6567e97dd93b1f11f185dc6
arch: amd64
compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
config: https://ci.syzbot.org/builds/2e25da54-5ae8-4f08-889d-30a90ffbe688/config
syz repro: https://ci.syzbot.org/findings/707c5fee-46af-42c3-9700-7fc53ef58eb2/syz_repro
=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
./include/linux/kvm_host.h:1084 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz.0.17/5871:
#0: ffff888113334b40 (&kvm->lock){+.+.}-{4:4}, at: kvm_arch_vm_ioctl+0x8d1/0x1990 arch/x86/kvm/x86.c:7320
stack backtrace:
CPU: 0 UID: 0 PID: 5871 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876
__kvm_memslots include/linux/kvm_host.h:1082 [inline]
kvm_memslots include/linux/kvm_host.h:1089 [inline]
gfn_to_memslot+0x3df/0x420 virt/kvm/kvm_main.c:2630
kvm_arch_vm_ioctl+0x1590/0x1990 arch/x86/kvm/x86.c:7340
kvm_vm_ioctl+0x8f7/0xd30 virt/kvm/kvm_main.c:5381
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+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd744b9ce59
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:00007fd7459b7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd744e15fa0 RCX: 00007fd744b9ce59
RDX: 0000000000000000 RSI: 000000000000ae60 RDI: 0000000000000004
RBP: 00007fd744c32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd744e16038 R14: 00007fd744e15fa0 R15: 00007ffe5f70a5a8
</TASK>
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
To test a patch for this bug, please reply with `#syz test`
(should be on a separate line).
The patch should be attached to the email.
Note: arguments like custom git repos and branches are not supported.
The email will later be sent to:
[bp@alien8.de corbet@lwn.net dave.hansen@linux.intel.com hpa@zytor.com kvm@vger.kernel.org linux-doc@vger.kernel.org linux-kernel@vger.kernel.org mingo@redhat.com pbonzini@redhat.com seanjc@google.com skhan@linuxfoundation.org tglx@kernel.org twiederh@redhat.com x86@kernel.org]
If the report looks fine to you, reply with:
#syz upstream
If the report is a false positive, reply with
#syz invalid
^ permalink raw reply [flat|nested] 2+ messages in thread* Re: [moderation/CI] Re: KVM: x86: Document and enforce APIC base memory hole
2026-07-06 15:08 [moderation/CI] Re: KVM: x86: Document and enforce APIC base memory hole syzbot ci
@ 2026-07-06 15:19 ` Aleksandr Nogikh
0 siblings, 0 replies; 2+ messages in thread
From: Aleksandr Nogikh @ 2026-07-06 15:19 UTC (permalink / raw)
To: syzbot ci; +Cc: syzkaller-upstream-moderation, syzbot
#syz upstream
On Mon, Jul 6, 2026 at 5:08 PM syzbot ci
<syzbot+cibf87a6f723c5bded@syzkaller.appspotmail.com> wrote:
>
> syzbot ci has tested the following series
>
> [v1] KVM: x86: Document and enforce APIC base memory hole
> https://lore.kernel.org/all/20260706092021.3625908-2-twiederh@redhat.com
> * [PATCH 1/4] KVM: x86: Document that KVM_CREATE_IRQCHIP must precede vcpu creation
> * [PATCH 2/4] KVM: x86: Document APIC base address constraint for in-kernel irqchip
> * [PATCH 3/4] KVM: x86: Reject KVM_CREATE_IRQCHIP if APIC base is already mapped
> * [PATCH 4/4] KVM: x86: Reject user memory regions covering the APIC base
>
> and found the following issue:
> WARNING: suspicious RCU usage in gfn_to_memslot
>
> Full report is available here:
> https://ci.syzbot.org/series/b02ae7eb-bae2-492f-88f2-fa1b511c93cf
>
> ***
>
> WARNING: suspicious RCU usage in gfn_to_memslot
>
> tree: kvm-next
> URL: https://kernel.googlesource.com/pub/scm/virt/kvm/kvm/
> base: 8cd9520d35a6c38db6567e97dd93b1f11f185dc6
> arch: amd64
> compiler: Debian clang version 22.1.6 (++20260514074242+fc4aad7b5db3-1~exp1~20260514074407.73), Debian LLD 22.1.6
> config: https://ci.syzbot.org/builds/2e25da54-5ae8-4f08-889d-30a90ffbe688/config
> syz repro: https://ci.syzbot.org/findings/707c5fee-46af-42c3-9700-7fc53ef58eb2/syz_repro
>
> =============================
> WARNING: suspicious RCU usage
> syzkaller #0 Not tainted
> -----------------------------
> ./include/linux/kvm_host.h:1084 suspicious rcu_dereference_check() usage!
>
> other info that might help us debug this:
>
>
> rcu_scheduler_active = 2, debug_locks = 1
> 1 lock held by syz.0.17/5871:
> #0: ffff888113334b40 (&kvm->lock){+.+.}-{4:4}, at: kvm_arch_vm_ioctl+0x8d1/0x1990 arch/x86/kvm/x86.c:7320
>
> stack backtrace:
> CPU: 0 UID: 0 PID: 5871 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
> Call Trace:
> <TASK>
> dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
> lockdep_rcu_suspicious+0x13f/0x1d0 kernel/locking/lockdep.c:6876
> __kvm_memslots include/linux/kvm_host.h:1082 [inline]
> kvm_memslots include/linux/kvm_host.h:1089 [inline]
> gfn_to_memslot+0x3df/0x420 virt/kvm/kvm_main.c:2630
> kvm_arch_vm_ioctl+0x1590/0x1990 arch/x86/kvm/x86.c:7340
> kvm_vm_ioctl+0x8f7/0xd30 virt/kvm/kvm_main.c:5381
> 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+0x174/0x580 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7fd744b9ce59
> 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:00007fd7459b7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00007fd744e15fa0 RCX: 00007fd744b9ce59
> RDX: 0000000000000000 RSI: 000000000000ae60 RDI: 0000000000000004
> RBP: 00007fd744c32e6f R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007fd744e16038 R14: 00007fd744e15fa0 R15: 00007ffe5f70a5a8
> </TASK>
>
>
> ***
>
> If these findings have caused you to resend the series or submit a
> separate fix, please add the following tag to your commit message:
> Tested-by: syzbot@syzkaller.appspotmail.com
>
> ---
> This report is generated by a bot. It may contain errors.
> syzbot ci engineers can be reached at syzkaller@googlegroups.com.
>
> To test a patch for this bug, please reply with `#syz test`
> (should be on a separate line).
>
> The patch should be attached to the email.
> Note: arguments like custom git repos and branches are not supported.
>
> The email will later be sent to:
> [bp@alien8.de corbet@lwn.net dave.hansen@linux.intel.com hpa@zytor.com kvm@vger.kernel.org linux-doc@vger.kernel.org linux-kernel@vger.kernel.org mingo@redhat.com pbonzini@redhat.com seanjc@google.com skhan@linuxfoundation.org tglx@kernel.org twiederh@redhat.com x86@kernel.org]
>
> If the report looks fine to you, reply with:
> #syz upstream
>
> If the report is a false positive, reply with
> #syz invalid
>
> --
> You received this message because you are subscribed to the Google Groups "syzkaller-upstream-moderation" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-upstream-moderation+unsubscribe@googlegroups.com.
> To view this discussion visit https://groups.google.com/d/msgid/syzkaller-upstream-moderation/6a4bc4de.b42ede87.8bd1.002c.GAE%40google.com.
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-07-06 15:19 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-06 15:08 [moderation/CI] Re: KVM: x86: Document and enforce APIC base memory hole syzbot ci
2026-07-06 15:19 ` Aleksandr Nogikh
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.