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