From 4c65fed8bdf96780735dbdb92a8bd0d6b6526cc3 Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Thu, 3 Dec 2015 18:54:17 +0530 Subject: [PATCH] ui: vnc: avoid floating point exception While sending 'SetPixelFormat' messages to a VNC server, the client could set the 'red-max', 'green-max' and 'blue-max' values to be zero. This leads to a floating point exception in write_png_palette while doing frame buffer updates. Reported-by: Lian Yihan Signed-off-by: Prasad J Pandit Reviewed-by: Gerd Hoffmann Signed-off-by: Peter Maydell Upstream-Status: Backport http://git.qemu.org/?p=qemu.git;a=commitdiff;h=4c65fed8bdf96780735dbdb92a8 CVE: CVE-2015-8504 [Yocto # 9013] Signed-off-by: Armin Kuster --- ui/vnc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) Index: qemu-2.2.0/ui/vnc.c =================================================================== --- qemu-2.2.0.orig/ui/vnc.c +++ qemu-2.2.0/ui/vnc.c @@ -2036,15 +2036,15 @@ static void set_pixel_format(VncState *v return; } - vs->client_pf.rmax = red_max; + vs->client_pf.rmax = red_max ? red_max : 0xFF; vs->client_pf.rbits = hweight_long(red_max); vs->client_pf.rshift = red_shift; vs->client_pf.rmask = red_max << red_shift; - vs->client_pf.gmax = green_max; + vs->client_pf.gmax = green_max ? green_max : 0xFF; vs->client_pf.gbits = hweight_long(green_max); vs->client_pf.gshift = green_shift; vs->client_pf.gmask = green_max << green_shift; - vs->client_pf.bmax = blue_max; + vs->client_pf.bmax = blue_max ? blue_max : 0xFF; vs->client_pf.bbits = hweight_long(blue_max); vs->client_pf.bshift = blue_shift; vs->client_pf.bmask = blue_max << blue_shift;