* [Qemu-devel] [PATCH] vnc: sanitize bits_per_pixel from the client
@ 2014-10-27 11:41 Petr Matousek
2014-10-27 11:53 ` Gerd Hoffmann
0 siblings, 1 reply; 2+ messages in thread
From: Petr Matousek @ 2014-10-27 11:41 UTC (permalink / raw)
To: qemu-devel; +Cc: Gerd Hoffmann, Anthony Liguori, qemu-stable
bits_per_pixel that are less than 8 could result in accessing
non-initialized buffers later in the code due to the expectation
that bytes_per_pixel value that is used to initialize these buffers is
never zero.
To fix this check that bits_per_pixel from the client is one of the
values that the rfb protocol specification allows.
This is CVE-2014-7815.
Signed-off-by: Petr Matousek <pmatouse@redhat.com>
---
ui/vnc.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/ui/vnc.c b/ui/vnc.c
index 0fe6eff..6c8fb1a 100644
--- a/ui/vnc.c
+++ b/ui/vnc.c
@@ -2026,6 +2026,17 @@ static void set_pixel_format(VncState *vs,
return;
}
+ switch(bits_per_pixel) {
+ case 8:
+ case 16:
+ case 32:
+ break;
+ default:
+ vnc_client_error(vs);
+ return;
+ break;
+ }
+
vs->client_pf.rmax = red_max;
vs->client_pf.rbits = hweight_long(red_max);
vs->client_pf.rshift = red_shift;
--
1.9.3
^ permalink raw reply related [flat|nested] 2+ messages in thread* Re: [Qemu-devel] [PATCH] vnc: sanitize bits_per_pixel from the client
2014-10-27 11:41 [Qemu-devel] [PATCH] vnc: sanitize bits_per_pixel from the client Petr Matousek
@ 2014-10-27 11:53 ` Gerd Hoffmann
0 siblings, 0 replies; 2+ messages in thread
From: Gerd Hoffmann @ 2014-10-27 11:53 UTC (permalink / raw)
To: Petr Matousek; +Cc: qemu-devel, Anthony Liguori, qemu-stable
On Mo, 2014-10-27 at 12:41 +0100, Petr Matousek wrote:
> bits_per_pixel that are less than 8 could result in accessing
> non-initialized buffers later in the code due to the expectation
> that bytes_per_pixel value that is used to initialize these buffers is
> never zero.
>
> To fix this check that bits_per_pixel from the client is one of the
> values that the rfb protocol specification allows.
>
> This is CVE-2014-7815.
>
> Signed-off-by: Petr Matousek <pmatouse@redhat.com>
applied minor codestyle fix & added to vnc patch queue.
thanks,
Gerd
^ permalink raw reply [flat|nested] 2+ messages in thread
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