From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=43987 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1OKO5R-0007jj-7s for qemu-devel@nongnu.org; Fri, 04 Jun 2010 00:00:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.69) (envelope-from ) id 1OKO5P-00011C-OA for qemu-devel@nongnu.org; Fri, 04 Jun 2010 00:00:49 -0400 Received: from adelie.canonical.com ([91.189.90.139]:56660) by eggs.gnu.org with esmtp (Exim 4.69) (envelope-from ) id 1OKO5P-000111-KM for qemu-devel@nongnu.org; Fri, 04 Jun 2010 00:00:47 -0400 Received: from loganberry.canonical.com ([91.189.90.37]) by adelie.canonical.com with esmtp (Exim 4.69 #1 (Debian)) id 1OKO5K-0002VA-CH for ; Fri, 04 Jun 2010 05:00:43 +0100 Received: from loganberry.canonical.com (localhost [127.0.0.1]) by loganberry.canonical.com (Postfix) with ESMTP id EDD572E826B for ; Fri, 4 Jun 2010 05:00:36 +0100 (BST) MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Date: Fri, 04 Jun 2010 03:52:07 -0000 From: sciencewhiz Sender: bounces@canonical.com References: <20100505164440.21255.94144.malonedeb@wampee.canonical.com> Message-Id: <20100604035208.15535.77467.malone@gandwana.canonical.com> Errors-To: bounces@canonical.com Subject: [Qemu-devel] [Bug 575887] Re: VNC heap corruption at 1400x1050 (with % 16 != 0) Reply-To: Bug 575887 <575887@bugs.launchpad.net> List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Where can I find a list of supported QEMU resolutions? -- = VNC heap corruption at 1400x1050 (with % 16 !=3D 0) https://bugs.launchpad.net/bugs/575887 You received this bug notification because you are a member of qemu- devel-ml, which is subscribed to QEMU. Status in QEMU: Invalid Bug description: vnc_refresh_server_surface assumes that the display width is a multiple of 16. If it's not, then it accesses beyond the end of the r= ow by a few bytes. On all but the last row, this is mostly harmless (it can result in unnecessarily marking the end of the row dirty), but on the last = row, it copies over heap metadata. This triggers a crash when changing resoluti= ons or disconnecting and reconnecting a client. I can trigger this reliably with a Windows 7 guest at 1400x1050 with -vga s= td. The attached patch (rather ugly, with debugging code for good measure) part= ially fixes the issue. There's still a black stripe on the right side of t= he screen, presumably because there are other bugs in vnc.c (or I messed up= the patch). I'm marking this as a security vulnerability because it allows the guest to= overwrite host memory. The same issue is tracked in Red Hat's bugzilla here: https://bugzilla.redhat.com/show_bug.cgi?id=3D583850