From abd84f26e0fe0bc9952d91fbd35fb3a7253cfecf Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Wed, 13 Apr 2022 20:54:45 -0400 Subject: [PATCH 1/2] display/qxl-render: fix race condition in qxl_cursor (CVE-2021-4207) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Jon Maloy RH-MergeRequest: 152: display/qxl-render: fix race condition in qxl_cursor (CVE-2021-4207) RH-Commit: [1/1] f05b9a956f2e0ca522b5be127beff813d04b5588 (jmaloy/qemu-kvm) RH-Bugzilla: 2040738 RH-Acked-by: Gerd Hoffmann RH-Acked-by: Mauro Matteo Cascella Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2040738 Upstream: Merged CVE: CVE-2021-4207 commit 9569f5cb5b4bffa9d3ebc8ba7da1e03830a9a895 Author: Mauro Matteo Cascella Date: Thu Apr 7 10:11:06 2022 +0200 display/qxl-render: fix race condition in qxl_cursor (CVE-2021-4207) Avoid fetching 'width' and 'height' a second time to prevent possible race condition. Refer to security advisory https://starlabs.sg/advisories/22-4207/ for more information. Fixes: CVE-2021-4207 Signed-off-by: Mauro Matteo Cascella Reviewed-by: Marc-André Lureau Message-Id: <20220407081106.343235-1-mcascell@redhat.com> Signed-off-by: Gerd Hoffmann (cherry picked from commit 9569f5cb5b4bffa9d3ebc8ba7da1e03830a9a895) Signed-off-by: Jon Maloy --- hw/display/qxl-render.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/display/qxl-render.c b/hw/display/qxl-render.c index d28849b121..237ed293ba 100644 --- a/hw/display/qxl-render.c +++ b/hw/display/qxl-render.c @@ -266,7 +266,7 @@ static QEMUCursor *qxl_cursor(PCIQXLDevice *qxl, QXLCursor *cursor, } break; case SPICE_CURSOR_TYPE_ALPHA: - size = sizeof(uint32_t) * cursor->header.width * cursor->header.height; + size = sizeof(uint32_t) * c->width * c->height; qxl_unpack_chunks(c->data, size, qxl, &cursor->chunk, group_id); if (qxl->debug > 2) { cursor_print_ascii_art(c, "qxl/alpha"); -- 2.27.0