From: "Philippe Mathieu-Daudé" <philmd@redhat.com>
To: Igor Mammedov <imammedo@redhat.com>, qemu-devel@nongnu.org
Cc: pbonzini@redhat.com, mst@redhat.com, ehabkost@redhat.com,
armbru@redhat.com, rth@twiddle.net
Subject: Re: [Qemu-devel] [PATCH v2] pc: fix possible NULL pointer dereference in pc_machine_get_device_memory_region_size()
Date: Tue, 25 Jun 2019 12:17:10 +0200 [thread overview]
Message-ID: <9826130c-0711-6d82-72ed-8e726dea8267@redhat.com> (raw)
In-Reply-To: <20190624090200.5383-1-imammedo@redhat.com>
On 6/24/19 11:02 AM, 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>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>
> v2:
> * fix missing return value assignment
> (Eduardo Habkost <ehabkost@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 e96360b47a..552f3401e2 100644
> --- a/hw/i386/pc.c
> +++ b/hw/i386/pc.c
> @@ -2458,7 +2458,11 @@ 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) {
> + value = memory_region_size(&ms->device_memory->mr);
> + }
>
> visit_type_int(v, name, &value, errp);
> }
>
next prev parent reply other threads:[~2019-06-25 10:24 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-24 9:02 [Qemu-devel] [PATCH v2] pc: fix possible NULL pointer dereference in pc_machine_get_device_memory_region_size() Igor Mammedov
2019-06-25 10:17 ` Philippe Mathieu-Daudé [this message]
2019-07-17 10:37 ` Michael S. Tsirkin
2019-07-17 11:22 ` Paolo Bonzini
2019-07-17 11:24 ` Michael S. Tsirkin
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