From eebe0b7905642a986cbce7406d6ab7bf78f3e210 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 24 Jan 2017 10:00:28 +0100 Subject: [PATCH] vnc: fix overflow in vnc_update_stats MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Commit "bea60dd ui/vnc: fix potential memory corruption issues" is incomplete. vnc_update_stats must calculate width and height the same way vnc_refresh_server_surface does it, to make sure we don't use width and height values larger than the qemu vnc server can handle. Commit "e22492d ui/vnc: disable adaptive update calculations if not needed" masks the issue in the default configuration. It triggers only in case the "lossy" option is set to "on" (default is "off"). Cc: Marc-André Lureau Signed-off-by: Gerd Hoffmann Reviewed-by: Marc-André Lureau Message-id: 1485248428-575-1-git-send-email-kraxel@redhat.com --- ui/vnc.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/ui/vnc.c b/ui/vnc.c index 6854fdb02f..cdeb79c3cc 100644 --- a/ui/vnc.c +++ b/ui/vnc.c @@ -2724,8 +2724,10 @@ static int vnc_refresh_lossy_rect(VncDisplay *vd, int x, int y) static int vnc_update_stats(VncDisplay *vd, struct timeval * tv) { - int width = pixman_image_get_width(vd->guest.fb); - int height = pixman_image_get_height(vd->guest.fb); + int width = MIN(pixman_image_get_width(vd->guest.fb), + pixman_image_get_width(vd->server)); + int height = MIN(pixman_image_get_height(vd->guest.fb), + pixman_image_get_height(vd->server)); int x, y; struct timeval res; int has_dirty = 0;