From ecc2505f20aebb75f7d078add292f5d705464b6d Mon Sep 17 00:00:00 2001 From: "Huawei Technologies Co., Ltd" Date: Fri, 5 Feb 2021 10:38:24 +0800 Subject: [PATCH] ati: use vga_read_byte in ati_cursor_define MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit fix CVE-2019-20808 This makes sure reads are confined to vga video memory. v3: use uint32_t, fix cut+paste bug. v2: fix ati_cursor_draw_line too. Reported-by: xu hang Signed-off-by: Gerd Hoffmann Reviewed-by: BALATON Zoltan Reviewed-by: Philippe Mathieu-Daudé Message-id: 20190917111441.27405-3-kraxel@redhat.com cherry-pick from aab0e2a661b2b6bf7915c0aefe807fb60d6d9d13 Signed-off-by: Jiajie Li --- ...e-vga_read_byte-in-ati_cursor_define.patch | 198 ++++++++++++++++++ 1 file changed, 198 insertions(+) create mode 100644 ati-use-vga_read_byte-in-ati_cursor_define.patch diff --git a/ati-use-vga_read_byte-in-ati_cursor_define.patch b/ati-use-vga_read_byte-in-ati_cursor_define.patch new file mode 100644 index 0000000..a4b7e80 --- /dev/null +++ b/ati-use-vga_read_byte-in-ati_cursor_define.patch @@ -0,0 +1,198 @@ +From 1ebe0e71d04bfdc76777a3a672e873f006d207e2 Mon Sep 17 00:00:00 2001 +From: Gerd Hoffmann +Date: Fri, 5 Feb 2021 10:38:24 +0800 +Subject: [PATCH] ati: use vga_read_byte in ati_cursor_define +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +fix CVE-2019-20808 + +This makes sure reads are confined to vga video memory. + +v3: use uint32_t, fix cut+paste bug. +v2: fix ati_cursor_draw_line too. + +Reported-by: xu hang +Signed-off-by: Gerd Hoffmann +Reviewed-by: BALATON Zoltan +Reviewed-by: Philippe Mathieu-Daudé +Message-id: 20190917111441.27405-3-kraxel@redhat.com + +cherry-pick from aab0e2a661b2b6bf7915c0aefe807fb60d6d9d13 +Signed-off-by: Jiajie Li +--- + hw/display/ati.c | 21 ++++++++--------- + hw/display/vga-access.h | 49 ++++++++++++++++++++++++++++++++++++++++ + hw/display/vga-helpers.h | 27 +--------------------- + 3 files changed, 60 insertions(+), 37 deletions(-) + create mode 100644 hw/display/vga-access.h + +diff --git a/hw/display/ati.c b/hw/display/ati.c +index 5943040416..b17569874e 100644 +--- a/hw/display/ati.c ++++ b/hw/display/ati.c +@@ -19,6 +19,7 @@ + #include "qemu/osdep.h" + #include "ati_int.h" + #include "ati_regs.h" ++#include "vga-access.h" + #include "vga_regs.h" + #include "qemu/log.h" + #include "qemu/module.h" +@@ -125,20 +126,19 @@ static void ati_vga_switch_mode(ATIVGAState *s) + static void ati_cursor_define(ATIVGAState *s) + { + uint8_t data[1024]; +- uint8_t *src; ++ uint32_t srcoff; + int i, j, idx = 0; + + if ((s->regs.cur_offset & BIT(31)) || s->cursor_guest_mode) { + return; /* Do not update cursor if locked or rendered by guest */ + } + /* FIXME handle cur_hv_offs correctly */ +- src = s->vga.vram_ptr + (s->regs.crtc_offset & 0x07ffffff) + +- s->regs.cur_offset - (s->regs.cur_hv_offs >> 16) - +- (s->regs.cur_hv_offs & 0xffff) * 16; ++ srcoff = s->regs.cur_offset - ++ (s->regs.cur_hv_offs >> 16) - (s->regs.cur_hv_offs & 0xffff) * 16; + for (i = 0; i < 64; i++) { + for (j = 0; j < 8; j++, idx++) { +- data[idx] = src[i * 16 + j]; +- data[512 + idx] = src[i * 16 + j + 8]; ++ data[idx] = vga_read_byte(&s->vga, srcoff + i * 16 + j); ++ data[512 + idx] = vga_read_byte(&s->vga, srcoff + i * 16 + j + 8); + } + } + if (!s->cursor) { +@@ -180,7 +180,7 @@ static void ati_cursor_invalidate(VGACommonState *vga) + static void ati_cursor_draw_line(VGACommonState *vga, uint8_t *d, int scr_y) + { + ATIVGAState *s = container_of(vga, ATIVGAState, vga); +- uint8_t *src; ++ uint32_t srcoff; + uint32_t *dp = (uint32_t *)d; + int i, j, h; + +@@ -190,14 +190,13 @@ static void ati_cursor_draw_line(VGACommonState *vga, uint8_t *d, int scr_y) + return; + } + /* FIXME handle cur_hv_offs correctly */ +- src = s->vga.vram_ptr + (s->regs.crtc_offset & 0x07ffffff) + +- s->cursor_offset + (scr_y - vga->hw_cursor_y) * 16; ++ srcoff = s->cursor_offset + (scr_y - vga->hw_cursor_y) * 16; + dp = &dp[vga->hw_cursor_x]; + h = ((s->regs.crtc_h_total_disp >> 16) + 1) * 8; + for (i = 0; i < 8; i++) { + uint32_t color; +- uint8_t abits = src[i]; +- uint8_t xbits = src[i + 8]; ++ uint8_t abits = vga_read_byte(vga, srcoff + i); ++ uint8_t xbits = vga_read_byte(vga, srcoff + i + 8); + for (j = 0; j < 8; j++, abits <<= 1, xbits <<= 1) { + if (abits & BIT(7)) { + if (xbits & BIT(7)) { +diff --git a/hw/display/vga-access.h b/hw/display/vga-access.h +new file mode 100644 +index 0000000000..c0fbd9958b +--- /dev/null ++++ b/hw/display/vga-access.h +@@ -0,0 +1,49 @@ ++/* ++ * QEMU VGA Emulator templates ++ * ++ * Copyright (c) 2003 Fabrice Bellard ++ * ++ * Permission is hereby granted, free of charge, to any person obtaining a copy ++ * of this software and associated documentation files (the "Software"), to deal ++ * in the Software without restriction, including without limitation the rights ++ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell ++ * copies of the Software, and to permit persons to whom the Software is ++ * furnished to do so, subject to the following conditions: ++ * ++ * The above copyright notice and this permission notice shall be included in ++ * all copies or substantial portions of the Software. ++ * ++ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR ++ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, ++ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL ++ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER ++ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, ++ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN ++ * THE SOFTWARE. ++ */ ++ ++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 = addr & vga->vbe_size_mask & ~1; ++ uint16_t *ptr = (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 = addr & vga->vbe_size_mask & ~1; ++ uint16_t *ptr = (uint16_t *)(vga->vram_ptr + offset); ++ return lduw_be_p(ptr); ++} ++ ++static inline uint32_t vga_read_dword_le(VGACommonState *vga, uint32_t addr) ++{ ++ uint32_t offset = addr & vga->vbe_size_mask & ~3; ++ uint32_t *ptr = (uint32_t *)(vga->vram_ptr + offset); ++ return ldl_le_p(ptr); ++} +diff --git a/hw/display/vga-helpers.h b/hw/display/vga-helpers.h +index 5a752b3f9e..5b6c02faa6 100644 +--- a/hw/display/vga-helpers.h ++++ b/hw/display/vga-helpers.h +@@ -21,6 +21,7 @@ + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN + * THE SOFTWARE. + */ ++#include "vga-access.h" + + static inline void vga_draw_glyph_line(uint8_t *d, uint32_t font_data, + uint32_t xorcol, uint32_t bgcol) +@@ -95,32 +96,6 @@ static void vga_draw_glyph9(uint8_t *d, int linesize, + } while (--h); + } + +-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 = addr & vga->vbe_size_mask & ~1; +- uint16_t *ptr = (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 = addr & vga->vbe_size_mask & ~1; +- uint16_t *ptr = (uint16_t *)(vga->vram_ptr + offset); +- return lduw_be_p(ptr); +-} +- +-static inline uint32_t vga_read_dword_le(VGACommonState *vga, uint32_t addr) +-{ +- uint32_t offset = addr & vga->vbe_size_mask & ~3; +- uint32_t *ptr = (uint32_t *)(vga->vram_ptr + offset); +- return ldl_le_p(ptr); +-} +- + /* + * 4 color mode + */ +-- +2.27.0 +