From: Paolo Bonzini <pbonzini@redhat.com>
To: Igor Mammedov <imammedo@redhat.com>, qemu-devel@nongnu.org
Cc: armbru@redhat.com, mst@redhat.com, ehabkost@redhat.com, rth@twiddle.net
Subject: Re: [Qemu-devel] [PATCH] pc: fix possible NULL pointer dereference in pc_machine_get_device_memory_region_size()
Date: Mon, 10 Jun 2019 15:57:25 +0200 [thread overview]
Message-ID: <5b8571b6-2347-ff62-2b0f-484fe47b476a@redhat.com> (raw)
In-Reply-To: <1560174635-22602-1-git-send-email-imammedo@redhat.com>
On 10/06/19 15:50, Igor Mammedov wrote:
> QEMU will crash when device-memory-region-size property is read if ms->device_memory
> wasn't initialized yet.
>
> Crash can be reproduced with:
> $QEMU -preconfig -qmp unix:qmp_socket,server,nowait &
> ./scripts/qmp/qom-get -s qmp_socket /machine.device-memory-region-size
>
> Instead of crashing return 0 if ms->device_memory hasn't been initialized.
>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
> v2:
> add reproducer to commit message
> (Markus Armbruster <armbru@redhat.com>)
>
> hw/i386/pc.c | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/hw/i386/pc.c b/hw/i386/pc.c
> index edc240b..1b7ead9 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -2459,7 +2459,11 @@ pc_machine_get_device_memory_region_size(Object *obj, Visitor *v,
> Error **errp)
> {
> MachineState *ms = MACHINE(obj);
> - int64_t value = memory_region_size(&ms->device_memory->mr);
> + int64_t value = 0;
> +
> + if (ms->device_memory) {
> + memory_region_size(&ms->device_memory->mr);
> + }
>
> visit_type_int(v, name, &value, errp);
> }
>
Queued, thanks.
Paolo
next prev parent reply other threads:[~2019-06-10 14:06 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-10 13:50 [Qemu-devel] [PATCH] pc: fix possible NULL pointer dereference in pc_machine_get_device_memory_region_size() Igor Mammedov
2019-06-10 13:57 ` Paolo Bonzini [this message]
2019-06-21 0:29 ` Paolo Bonzini
2019-06-21 1:46 ` Eduardo Habkost
2019-06-24 9:01 ` Igor Mammedov
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