From nobody Mon Apr 29 11:45:32 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 1503566446879967.0707314484408; Thu, 24 Aug 2017 02:20:46 -0700 (PDT) Received: from localhost ([::1]:47393 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dkoJh-0005GI-Ig for importer@patchew.org; Thu, 24 Aug 2017 05:20:45 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45050) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dkoIH-0004Mv-5A for qemu-devel@nongnu.org; Thu, 24 Aug 2017 05:19:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dkoIB-0002oy-S3 for qemu-devel@nongnu.org; Thu, 24 Aug 2017 05:19:16 -0400 Received: from mx1.redhat.com ([209.132.183.28]:40810) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dkoIB-0002ol-IC for qemu-devel@nongnu.org; Thu, 24 Aug 2017 05:19:11 -0400 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7E3B95D697; Thu, 24 Aug 2017 09:19:10 +0000 (UTC) Received: from sirius.home.kraxel.org (ovpn-116-82.ams2.redhat.com [10.36.116.82]) by smtp.corp.redhat.com (Postfix) with ESMTP id EE62717F59; Thu, 24 Aug 2017 09:19:07 +0000 (UTC) Received: by sirius.home.kraxel.org (Postfix, from userid 1000) id 2D60C3FBB7; Thu, 24 Aug 2017 11:19:07 +0200 (CEST) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 7E3B95D697 Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx10.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=kraxel@redhat.com From: Gerd Hoffmann To: qemu-devel@nongnu.org Date: Thu, 24 Aug 2017 11:19:07 +0200 Message-Id: <20170824091907.17676-1-kraxel@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Thu, 24 Aug 2017 09:19:10 +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] vga: stop passing pointers to vga_draw_line* functions 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" Instead pass around the address (aka offset into vga memory). Add vga_read_* helper functions which apply vbe_size_mask to the address, to make sure the address stays within the valid range, simliar to the cirrus blitter fixes (commits ffaf857778 and 026aeffcb4). Impact: DoS for priviledged guest users. qemu crashes with a segfault, when hitting the guard page after vga memory allocation, while reading vga memory for display updates. Fixes: CVE-2017-xxxx Cc: P J P Reported-by: David Buchanan Signed-off-by: Gerd Hoffmann --- hw/display/vga-helpers.h | 202 ++++++++++++++++++++++++++-----------------= ---- hw/display/vga_int.h | 1 + hw/display/vga.c | 5 +- 3 files changed, 114 insertions(+), 94 deletions(-) diff --git a/hw/display/vga-helpers.h b/hw/display/vga-helpers.h index 94f6de2046..5a752b3f9e 100644 --- a/hw/display/vga-helpers.h +++ b/hw/display/vga-helpers.h @@ -95,20 +95,46 @@ static void vga_draw_glyph9(uint8_t *d, int linesize, } while (--h); } =20 +static inline uint8_t vga_read_byte(VGACommonState *vga, uint32_t addr) +{ + return vga->vram_ptr[addr & vga->vbe_size_mask]; +} + +static inline uint16_t vga_read_word_le(VGACommonState *vga, uint32_t addr) +{ + uint32_t offset =3D addr & vga->vbe_size_mask & ~1; + uint16_t *ptr =3D (uint16_t *)(vga->vram_ptr + offset); + return lduw_le_p(ptr); +} + +static inline uint16_t vga_read_word_be(VGACommonState *vga, uint32_t addr) +{ + uint32_t offset =3D addr & vga->vbe_size_mask & ~1; + uint16_t *ptr =3D (uint16_t *)(vga->vram_ptr + offset); + return lduw_be_p(ptr); +} + +static inline uint32_t vga_read_dword_le(VGACommonState *vga, uint32_t add= r) +{ + uint32_t offset =3D addr & vga->vbe_size_mask & ~3; + uint32_t *ptr =3D (uint32_t *)(vga->vram_ptr + offset); + return ldl_le_p(ptr); +} + /* * 4 color mode */ -static void vga_draw_line2(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line2(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { uint32_t plane_mask, *palette, data, v; int x; =20 - palette =3D s1->last_palette; - plane_mask =3D mask16[s1->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; + palette =3D vga->last_palette; + plane_mask =3D mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; width >>=3D 3; for(x =3D 0; x < width; x++) { - data =3D ((uint32_t *)s)[0]; + data =3D vga_read_dword_le(vga, addr); data &=3D plane_mask; v =3D expand2[GET_PLANE(data, 0)]; v |=3D expand2[GET_PLANE(data, 2)] << 2; @@ -124,7 +150,7 @@ static void vga_draw_line2(VGACommonState *s1, uint8_t = *d, ((uint32_t *)d)[6] =3D palette[(v >> 4) & 0xf]; ((uint32_t *)d)[7] =3D palette[(v >> 0) & 0xf]; d +=3D 32; - s +=3D 4; + addr +=3D 4; } } =20 @@ -134,17 +160,17 @@ static void vga_draw_line2(VGACommonState *s1, uint8_= t *d, /* * 4 color mode, dup2 horizontal */ -static void vga_draw_line2d2(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line2d2(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { uint32_t plane_mask, *palette, data, v; int x; =20 - palette =3D s1->last_palette; - plane_mask =3D mask16[s1->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; + palette =3D vga->last_palette; + plane_mask =3D mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; width >>=3D 3; for(x =3D 0; x < width; x++) { - data =3D ((uint32_t *)s)[0]; + data =3D vga_read_dword_le(vga, addr); data &=3D plane_mask; v =3D expand2[GET_PLANE(data, 0)]; v |=3D expand2[GET_PLANE(data, 2)] << 2; @@ -160,24 +186,24 @@ static void vga_draw_line2d2(VGACommonState *s1, uint= 8_t *d, PUT_PIXEL2(d, 6, palette[(v >> 4) & 0xf]); PUT_PIXEL2(d, 7, palette[(v >> 0) & 0xf]); d +=3D 64; - s +=3D 4; + addr +=3D 4; } } =20 /* * 16 color mode */ -static void vga_draw_line4(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line4(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { uint32_t plane_mask, data, v, *palette; int x; =20 - palette =3D s1->last_palette; - plane_mask =3D mask16[s1->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; + palette =3D vga->last_palette; + plane_mask =3D mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; width >>=3D 3; for(x =3D 0; x < width; x++) { - data =3D ((uint32_t *)s)[0]; + data =3D vga_read_dword_le(vga, addr); data &=3D plane_mask; v =3D expand4[GET_PLANE(data, 0)]; v |=3D expand4[GET_PLANE(data, 1)] << 1; @@ -192,24 +218,24 @@ static void vga_draw_line4(VGACommonState *s1, uint8_= t *d, ((uint32_t *)d)[6] =3D palette[(v >> 4) & 0xf]; ((uint32_t *)d)[7] =3D palette[(v >> 0) & 0xf]; d +=3D 32; - s +=3D 4; + addr +=3D 4; } } =20 /* * 16 color mode, dup2 horizontal */ -static void vga_draw_line4d2(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line4d2(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { uint32_t plane_mask, data, v, *palette; int x; =20 - palette =3D s1->last_palette; - plane_mask =3D mask16[s1->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; + palette =3D vga->last_palette; + plane_mask =3D mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf]; width >>=3D 3; for(x =3D 0; x < width; x++) { - data =3D ((uint32_t *)s)[0]; + data =3D vga_read_dword_le(vga, addr); data &=3D plane_mask; v =3D expand4[GET_PLANE(data, 0)]; v |=3D expand4[GET_PLANE(data, 1)] << 1; @@ -224,7 +250,7 @@ static void vga_draw_line4d2(VGACommonState *s1, uint8_= t *d, PUT_PIXEL2(d, 6, palette[(v >> 4) & 0xf]); PUT_PIXEL2(d, 7, palette[(v >> 0) & 0xf]); d +=3D 64; - s +=3D 4; + addr +=3D 4; } } =20 @@ -233,21 +259,21 @@ static void vga_draw_line4d2(VGACommonState *s1, uint= 8_t *d, * * XXX: add plane_mask support (never used in standard VGA modes) */ -static void vga_draw_line8d2(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line8d2(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { uint32_t *palette; int x; =20 - palette =3D s1->last_palette; + palette =3D vga->last_palette; width >>=3D 3; for(x =3D 0; x < width; x++) { - PUT_PIXEL2(d, 0, palette[s[0]]); - PUT_PIXEL2(d, 1, palette[s[1]]); - PUT_PIXEL2(d, 2, palette[s[2]]); - PUT_PIXEL2(d, 3, palette[s[3]]); + PUT_PIXEL2(d, 0, palette[vga_read_byte(vga, addr + 0)]); + PUT_PIXEL2(d, 1, palette[vga_read_byte(vga, addr + 1)]); + PUT_PIXEL2(d, 2, palette[vga_read_byte(vga, addr + 2)]); + PUT_PIXEL2(d, 3, palette[vga_read_byte(vga, addr + 3)]); d +=3D 32; - s +=3D 4; + addr +=3D 4; } } =20 @@ -256,63 +282,63 @@ static void vga_draw_line8d2(VGACommonState *s1, uint= 8_t *d, * * XXX: add plane_mask support (never used in standard VGA modes) */ -static void vga_draw_line8(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line8(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { uint32_t *palette; int x; =20 - palette =3D s1->last_palette; + palette =3D vga->last_palette; width >>=3D 3; for(x =3D 0; x < width; x++) { - ((uint32_t *)d)[0] =3D palette[s[0]]; - ((uint32_t *)d)[1] =3D palette[s[1]]; - ((uint32_t *)d)[2] =3D palette[s[2]]; - ((uint32_t *)d)[3] =3D palette[s[3]]; - ((uint32_t *)d)[4] =3D palette[s[4]]; - ((uint32_t *)d)[5] =3D palette[s[5]]; - ((uint32_t *)d)[6] =3D palette[s[6]]; - ((uint32_t *)d)[7] =3D palette[s[7]]; + ((uint32_t *)d)[0] =3D palette[vga_read_byte(vga, addr + 0)]; + ((uint32_t *)d)[1] =3D palette[vga_read_byte(vga, addr + 1)]; + ((uint32_t *)d)[2] =3D palette[vga_read_byte(vga, addr + 2)]; + ((uint32_t *)d)[3] =3D palette[vga_read_byte(vga, addr + 3)]; + ((uint32_t *)d)[4] =3D palette[vga_read_byte(vga, addr + 4)]; + ((uint32_t *)d)[5] =3D palette[vga_read_byte(vga, addr + 5)]; + ((uint32_t *)d)[6] =3D palette[vga_read_byte(vga, addr + 6)]; + ((uint32_t *)d)[7] =3D palette[vga_read_byte(vga, addr + 7)]; d +=3D 32; - s +=3D 8; + addr +=3D 8; } } =20 /* * 15 bit color */ -static void vga_draw_line15_le(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line15_le(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { int w; uint32_t v, r, g, b; =20 w =3D width; do { - v =3D lduw_le_p((void *)s); + v =3D vga_read_word_le(vga, addr); r =3D (v >> 7) & 0xf8; g =3D (v >> 2) & 0xf8; b =3D (v << 3) & 0xf8; ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 2; + addr +=3D 2; d +=3D 4; } while (--w !=3D 0); } =20 -static void vga_draw_line15_be(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line15_be(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { int w; uint32_t v, r, g, b; =20 w =3D width; do { - v =3D lduw_be_p((void *)s); + v =3D vga_read_word_be(vga, addr); r =3D (v >> 7) & 0xf8; g =3D (v >> 2) & 0xf8; b =3D (v << 3) & 0xf8; ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 2; + addr +=3D 2; d +=3D 4; } while (--w !=3D 0); } @@ -320,38 +346,38 @@ static void vga_draw_line15_be(VGACommonState *s1, ui= nt8_t *d, /* * 16 bit color */ -static void vga_draw_line16_le(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line16_le(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { int w; uint32_t v, r, g, b; =20 w =3D width; do { - v =3D lduw_le_p((void *)s); + v =3D vga_read_word_le(vga, addr); r =3D (v >> 8) & 0xf8; g =3D (v >> 3) & 0xfc; b =3D (v << 3) & 0xf8; ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 2; + addr +=3D 2; d +=3D 4; } while (--w !=3D 0); } =20 -static void vga_draw_line16_be(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line16_be(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { int w; uint32_t v, r, g, b; =20 w =3D width; do { - v =3D lduw_be_p((void *)s); + v =3D vga_read_word_be(vga, addr); r =3D (v >> 8) & 0xf8; g =3D (v >> 3) & 0xfc; b =3D (v << 3) & 0xf8; ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 2; + addr +=3D 2; d +=3D 4; } while (--w !=3D 0); } @@ -359,36 +385,36 @@ static void vga_draw_line16_be(VGACommonState *s1, ui= nt8_t *d, /* * 24 bit color */ -static void vga_draw_line24_le(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line24_le(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { int w; uint32_t r, g, b; =20 w =3D width; do { - b =3D s[0]; - g =3D s[1]; - r =3D s[2]; + b =3D vga_read_byte(vga, addr + 0); + g =3D vga_read_byte(vga, addr + 1); + r =3D vga_read_byte(vga, addr + 2); ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 3; + addr +=3D 3; d +=3D 4; } while (--w !=3D 0); } =20 -static void vga_draw_line24_be(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line24_be(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { int w; uint32_t r, g, b; =20 w =3D width; do { - r =3D s[0]; - g =3D s[1]; - b =3D s[2]; + r =3D vga_read_byte(vga, addr + 0); + g =3D vga_read_byte(vga, addr + 1); + b =3D vga_read_byte(vga, addr + 2); ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 3; + addr +=3D 3; d +=3D 4; } while (--w !=3D 0); } @@ -396,44 +422,36 @@ static void vga_draw_line24_be(VGACommonState *s1, ui= nt8_t *d, /* * 32 bit color */ -static void vga_draw_line32_le(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line32_le(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { -#ifndef HOST_WORDS_BIGENDIAN - memcpy(d, s, width * 4); -#else int w; uint32_t r, g, b; =20 w =3D width; do { - b =3D s[0]; - g =3D s[1]; - r =3D s[2]; + b =3D vga_read_byte(vga, addr + 0); + g =3D vga_read_byte(vga, addr + 1); + r =3D vga_read_byte(vga, addr + 2); ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 4; + addr +=3D 4; d +=3D 4; } while (--w !=3D 0); -#endif } =20 -static void vga_draw_line32_be(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width) +static void vga_draw_line32_be(VGACommonState *vga, uint8_t *d, + uint32_t addr, int width) { -#ifdef HOST_WORDS_BIGENDIAN - memcpy(d, s, width * 4); -#else int w; uint32_t r, g, b; =20 w =3D width; do { - r =3D s[1]; - g =3D s[2]; - b =3D s[3]; + r =3D vga_read_byte(vga, addr + 1); + g =3D vga_read_byte(vga, addr + 2); + b =3D vga_read_byte(vga, addr + 3); ((uint32_t *)d)[0] =3D rgb_to_pixel32(r, g, b); - s +=3D 4; + addr +=3D 4; d +=3D 4; } while (--w !=3D 0); -#endif } diff --git a/hw/display/vga_int.h b/hw/display/vga_int.h index dd6c958da3..ad34a1f048 100644 --- a/hw/display/vga_int.h +++ b/hw/display/vga_int.h @@ -94,6 +94,7 @@ typedef struct VGACommonState { uint32_t vram_size; uint32_t vram_size_mb; /* property */ uint32_t vbe_size; + uint32_t vbe_size_mask; uint32_t latch; bool has_chain4_alias; MemoryRegion chain4_alias; diff --git a/hw/display/vga.c b/hw/display/vga.c index 63421f9ee8..4c2ee0be28 100644 --- a/hw/display/vga.c +++ b/hw/display/vga.c @@ -1005,7 +1005,7 @@ void vga_mem_writeb(VGACommonState *s, hwaddr addr, u= int32_t val) } =20 typedef void vga_draw_line_func(VGACommonState *s1, uint8_t *d, - const uint8_t *s, int width); + uint32_t srcaddr, int width); =20 #include "vga-helpers.h" =20 @@ -1660,7 +1660,7 @@ static void vga_draw_graphic(VGACommonState *s, int f= ull_update) if (y_start < 0) y_start =3D y; if (!(is_buffer_shared(surface))) { - vga_draw_line(s, d, s->vram_ptr + addr, width); + vga_draw_line(s, d, addr, width); if (s->cursor_draw_line) s->cursor_draw_line(s, d, y); } @@ -2164,6 +2164,7 @@ void vga_common_init(VGACommonState *s, Object *obj, = bool global_vmstate) if (!s->vbe_size) { s->vbe_size =3D s->vram_size; } + s->vbe_size_mask =3D s->vbe_size - 1; =20 s->is_vbe_vmstate =3D 1; memory_region_init_ram_nomigrate(&s->vram, obj, "vga.vram", s->vram_si= ze, --=20 2.9.3