From nobody Sat May 4 11:08:44 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1507634101882465.77811852337334; Tue, 10 Oct 2017 04:15:01 -0700 (PDT) Received: from localhost ([::1]:34165 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1sV1-0006qw-2c for importer@patchew.org; Tue, 10 Oct 2017 07:14:59 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44179) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1sSw-0005Ry-8u for qemu-devel@nongnu.org; Tue, 10 Oct 2017 07:12:55 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1sSu-0002iH-91 for qemu-devel@nongnu.org; Tue, 10 Oct 2017 07:12:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:53410) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e1sSu-0002hv-3F for qemu-devel@nongnu.org; Tue, 10 Oct 2017 07:12:48 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 141FFC04AC6C; Tue, 10 Oct 2017 11:12:47 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-239.ams2.redhat.com [10.36.116.239]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6967563BA7; Tue, 10 Oct 2017 11:12:41 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id A000916A887; Tue, 10 Oct 2017 13:12:40 +0200 (CEST) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 141FFC04AC6C Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx07.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=kraxel@redhat.com From: Gerd Hoffmann To: qemu-devel@nongnu.org Date: Tue, 10 Oct 2017 13:12:39 +0200 Message-Id: <20171010111240.27607-2-kraxel@redhat.com> In-Reply-To: <20171010111240.27607-1-kraxel@redhat.com> References: <20171010111240.27607-1-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.31]); Tue, 10 Oct 2017 11:12:47 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 1/2] vga: drop line_offset variable X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gerd Hoffmann , d@vidbuchanan.co.uk Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" --- hw/display/vga.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/hw/display/vga.c b/hw/display/vga.c index ed24ef7076..bf774e3402 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -1464,7 +1464,7 @@ static void vga_draw_graphic(VGACommonState *s, int f= ull_update) { DisplaySurface *surface =3D qemu_console_surface(s->con); int y1, y, update, linesize, y_start, double_scan, mask, depth; - int width, height, shift_control, line_offset, bwidth, bits; + int width, height, shift_control, bwidth, bits; ram_addr_t page0, page1; DirtyBitmapSnapshot *snap =3D NULL; int disp_width, multi_scan, multi_run; @@ -1614,7 +1614,6 @@ static void vga_draw_graphic(VGACommonState *s, int f= ull_update) s->cursor_invalidate(s); } =20 - line_offset =3D s->line_offset; #if 0 printf("w=3D%d h=3D%d v=3D%d line_offset=3D%d cr[0x09]=3D0x%02x cr[0x1= 7]=3D0x%02x linecmp=3D%d sr[0x01]=3D0x%02x\n", width, height, v, line_offset, s->cr[9], s->cr[VGA_CRTC_MODE], @@ -1629,7 +1628,7 @@ static void vga_draw_graphic(VGACommonState *s, int f= ull_update) =20 if (!full_update) { ram_addr_t region_start =3D addr1; - ram_addr_t region_end =3D addr1 + line_offset * height; + ram_addr_t region_end =3D addr1 + s->line_offset * height; vga_sync_dirty_bitmap(s); if (s->line_compare < height) { /* split screen mode */ @@ -1681,7 +1680,7 @@ static void vga_draw_graphic(VGACommonState *s, int f= ull_update) if (!multi_run) { mask =3D (s->cr[VGA_CRTC_MODE] & 3) ^ 3; if ((y1 & mask) =3D=3D mask) - addr1 +=3D line_offset; + addr1 +=3D s->line_offset; y1++; multi_run =3D multi_scan; } else { --=20 2.9.3 From nobody Sat May 4 11:08:44 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1507634081461290.75850201492517; Tue, 10 Oct 2017 04:14:41 -0700 (PDT) Received: from localhost ([::1]:34163 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1sUc-0006VT-MG for importer@patchew.org; Tue, 10 Oct 2017 07:14:34 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:44175) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e1sSw-0005Ru-7i for qemu-devel@nongnu.org; Tue, 10 Oct 2017 07:12:51 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e1sSr-0002gw-Da for qemu-devel@nongnu.org; Tue, 10 Oct 2017 07:12:50 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52998) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e1sSr-0002fo-4u for qemu-devel@nongnu.org; Tue, 10 Oct 2017 07:12:45 -0400 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id CB4B5285A0; Tue, 10 Oct 2017 11:12:43 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-239.ams2.redhat.com [10.36.116.239]) by smtp.corp.redhat.com (Postfix) with ESMTP id 71E4251891; Tue, 10 Oct 2017 11:12:41 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id A759716A88F; Tue, 10 Oct 2017 13:12:40 +0200 (CEST) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com CB4B5285A0 Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx06.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=kraxel@redhat.com From: Gerd Hoffmann To: qemu-devel@nongnu.org Date: Tue, 10 Oct 2017 13:12:40 +0200 Message-Id: <20171010111240.27607-3-kraxel@redhat.com> In-Reply-To: <20171010111240.27607-1-kraxel@redhat.com> References: <20171010111240.27607-1-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.30]); Tue, 10 Oct 2017 11:12:43 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 Subject: [Qemu-devel] [PATCH v2 2/2] vga: handle cirrus vbe mode wraparounds. X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gerd Hoffmann , d@vidbuchanan.co.uk, P J P Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Commit "3d90c62548 vga: stop passing pointers to vga_draw_line* functions" is incomplete. It doesn't handle the case that the vga rendering code tries to create a shared surface, i.e. a pixman image backed by vga video memory. That can not work in case the guest display wraps from end of video memory to the start. So force shadowing in that case. Also adjust the snapshot region calculation. Can trigger with cirrus only, when programming vbe modes using the bochs api (stdvga, also qxl and virtio-vga in vga compat mode) wrap arounds can't happen. Fixes: CVE-2017-13672 Fixes: 3d90c6254863693a6b13d918d2b8682e08bbc681 Cc: P J P Reported-by: David Buchanan Signed-off-by: Gerd Hoffmann --- hw/display/vga.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/hw/display/vga.c b/hw/display/vga.c index bf774e3402..1afceb6f16 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -1465,13 +1465,13 @@ static void vga_draw_graphic(VGACommonState *s, int= full_update) DisplaySurface *surface =3D qemu_console_surface(s->con); int y1, y, update, linesize, y_start, double_scan, mask, depth; int width, height, shift_control, bwidth, bits; - ram_addr_t page0, page1; + ram_addr_t page0, page1, region_start, region_end; DirtyBitmapSnapshot *snap =3D NULL; int disp_width, multi_scan, multi_run; uint8_t *d; uint32_t v, addr1, addr; vga_draw_line_func *vga_draw_line =3D NULL; - bool share_surface; + bool share_surface, force_shadow =3D false; pixman_format_code_t format; #ifdef HOST_WORDS_BIGENDIAN bool byteswap =3D !s->big_endian_fb; @@ -1484,6 +1484,15 @@ static void vga_draw_graphic(VGACommonState *s, int = full_update) s->get_resolution(s, &width, &height); disp_width =3D width; =20 + region_start =3D (s->start_addr * 4); + region_end =3D region_start + s->line_offset * height; + if (region_end > s->vbe_size) { + /* wraps around (can happen with cirrus vbe modes) */ + region_start =3D 0; + region_end =3D s->vbe_size; + force_shadow =3D true; + } + shift_control =3D (s->gr[VGA_GFX_MODE] >> 5) & 3; double_scan =3D (s->cr[VGA_CRTC_MAX_SCAN] >> 7); if (shift_control !=3D 1) { @@ -1523,7 +1532,7 @@ static void vga_draw_graphic(VGACommonState *s, int f= ull_update) format =3D qemu_default_pixman_format(depth, !byteswap); if (format) { share_surface =3D dpy_gfx_check_format(s->con, format) - && !s->force_shadow; + && !s->force_shadow && !force_shadow; } else { share_surface =3D false; } @@ -1627,8 +1636,6 @@ static void vga_draw_graphic(VGACommonState *s, int f= ull_update) y1 =3D 0; =20 if (!full_update) { - ram_addr_t region_start =3D addr1; - ram_addr_t region_end =3D addr1 + s->line_offset * height; vga_sync_dirty_bitmap(s); if (s->line_compare < height) { /* split screen mode */ @@ -1651,10 +1658,17 @@ static void vga_draw_graphic(VGACommonState *s, int= full_update) addr =3D (addr & ~0x8000) | ((y1 & 2) << 14); } update =3D full_update; - page0 =3D addr; - page1 =3D addr + bwidth - 1; + page0 =3D addr & s->vbe_size_mask; + page1 =3D (addr + bwidth - 1) & s->vbe_size_mask; if (full_update) { update =3D 1; + } else if (page1 < page0) { + /* scanline wraps from end of video memory to the start */ + assert(force_shadow); + update =3D memory_region_snapshot_get_dirty(&s->vram, snap, + page0, 0); + update |=3D memory_region_snapshot_get_dirty(&s->vram, snap, + page1, 0); } else { update =3D memory_region_snapshot_get_dirty(&s->vram, snap, page0, page1 - page0= ); --=20 2.9.3