linux-kernel - Re: [PATCH stable-4.19 1/2] KVM: nVMX: do not use dangling shadow VMCS after guest reset

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Mon, 29 Jul 2019 10:58:30 +0200
From:   Jack Wang <jack.wang.usish@...il.com>
To:     Vitaly Kuznetsov <vkuznets@...hat.com>
Cc:     stable@...r.kernel.org, kvm@...r.kernel.org,
        linux-kernel@...r.kernel.org, Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>
Subject: Re: [PATCH stable-4.19 1/2] KVM: nVMX: do not use dangling shadow
 VMCS after guest reset

Vitaly Kuznetsov <vkuznets@...hat.com> 于2019年7月25日周四 下午3:29写道：
>
> From: Paolo Bonzini <pbonzini@...hat.com>
>
> [ Upstream commit 88dddc11a8d6b09201b4db9d255b3394d9bc9e57 ]
>
> If a KVM guest is reset while running a nested guest, free_nested will
> disable the shadow VMCS execution control in the vmcs01.  However,
> on the next KVM_RUN vmx_vcpu_run would nevertheless try to sync
> the VMCS12 to the shadow VMCS which has since been freed.
>
> This causes a vmptrld of a NULL pointer on my machime, but Jan reports
> the host to hang altogether.  Let's see how much this trivial patch fixes.
>
> Reported-by: Jan Kiszka <jan.kiszka@...mens.com>
> Cc: Liran Alon <liran.alon@...cle.com>
> Cc: stable@...r.kernel.org
> Signed-off-by: Paolo Bonzini <pbonzini@...hat.com>

Hi all,

Do we need to backport the fix also to stable 4.14?  It applies
cleanly and compiles fine.

Regards,
Jack Wang