From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:41886) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WUd1F-0000rx-ER for qemu-devel@nongnu.org; Mon, 31 Mar 2014 10:17:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WUd19-0000jy-Aw for qemu-devel@nongnu.org; Mon, 31 Mar 2014 10:16:57 -0400 Date: Mon, 31 Mar 2014 17:17:16 +0300 From: "Michael S. Tsirkin" Message-ID: <1396275242-10810-22-git-send-email-mst@redhat.com> References: <1396275242-10810-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1396275242-10810-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PATCH v4 21/30] ssd0323: fix buffer overun on invalid state load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Peter Crosthwaite , mdroth@linux.vnet.ibm.com, qemu-stable@nongnu.org, dgilbert@redhat.com, Gerd Hoffmann , Paolo Bonzini , =?us-ascii?B?PT9VVEYtOD9xP0FuZHJlYXM9MjBGPUMzPUE0cmJlcj89?= CVE-2013-4538 s->cmd_len used as index in ssd0323_transfer() to store 32-bit field. Possible this field might then be supplied by guest to overwrite a return addr somewhere. Same for row/col fields, which are indicies into framebuffer array. To fix validate after load. Signed-off-by: Michael S. Tsirkin --- hw/display/ssd0323.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/hw/display/ssd0323.c b/hw/display/ssd0323.c index 971152e..b520c69 100644 --- a/hw/display/ssd0323.c +++ b/hw/display/ssd0323.c @@ -312,13 +312,22 @@ static int ssd0323_load(QEMUFile *f, void *opaque, int version_id) return -EINVAL; s->cmd_len = qemu_get_be32(f); + if (s->cmd_len < 0 || s->cmd_len > ARRAY_SIZE(s->cmd_data)) { + return -EINVAL; + } s->cmd = qemu_get_be32(f); for (i = 0; i < 8; i++) s->cmd_data[i] = qemu_get_be32(f); s->row = qemu_get_be32(f); + if (s->row < 0 || s->row >= 80 ) { + return -EINVAL; + } s->row_start = qemu_get_be32(f); s->row_end = qemu_get_be32(f); s->col = qemu_get_be32(f); + if (s->col < 0 || s->col >= 64 ) { + return -EINVAL; + } s->col_start = qemu_get_be32(f); s->col_end = qemu_get_be32(f); s->redraw = qemu_get_be32(f); -- MST