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128ed2278c
qemu/hw/display/vga-helpers.h
Gerd Hoffmann 3d90c62548 vga: stop passing pointers to vga_draw_line* functions 
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, similar to the cirrus blitter fixes (commits ffaf857778
and 026aeffcb4).

Impact:  DoS for privileged 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-2017-13672
Cc: P J P <ppandit@redhat.com>
Reported-by: David Buchanan <d@vidbuchanan.co.uk>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20170828122906.18993-1-kraxel@redhat.com
2017-09-01 13:52:43 +02:00

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/*
* 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 void vga_draw_glyph_line(uint8_t *d, uint32_t font_data,
uint32_t xorcol, uint32_t bgcol)
{
((uint32_t *)d)[0] = (-((font_data >> 7)) & xorcol) ^ bgcol;
((uint32_t *)d)[1] = (-((font_data >> 6) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[2] = (-((font_data >> 5) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[3] = (-((font_data >> 4) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[4] = (-((font_data >> 3) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[5] = (-((font_data >> 2) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[6] = (-((font_data >> 1) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[7] = (-((font_data >> 0) & 1) & xorcol) ^ bgcol;
}
static void vga_draw_glyph8(uint8_t *d, int linesize,
const uint8_t *font_ptr, int h,
uint32_t fgcol, uint32_t bgcol)
{
uint32_t font_data, xorcol;
xorcol = bgcol ^ fgcol;
do {
font_data = font_ptr[0];
vga_draw_glyph_line(d, font_data, xorcol, bgcol);
font_ptr += 4;
d += linesize;
} while (--h);
}
static void vga_draw_glyph16(uint8_t *d, int linesize,
const uint8_t *font_ptr, int h,
uint32_t fgcol, uint32_t bgcol)
{
uint32_t font_data, xorcol;
xorcol = bgcol ^ fgcol;
do {
font_data = font_ptr[0];
vga_draw_glyph_line(d, expand4to8[font_data >> 4],
xorcol, bgcol);
vga_draw_glyph_line(d + 32, expand4to8[font_data & 0x0f],
xorcol, bgcol);
font_ptr += 4;
d += linesize;
} while (--h);
}
static void vga_draw_glyph9(uint8_t *d, int linesize,
const uint8_t *font_ptr, int h,
uint32_t fgcol, uint32_t bgcol, int dup9)
{
uint32_t font_data, xorcol, v;
xorcol = bgcol ^ fgcol;
do {
font_data = font_ptr[0];
((uint32_t *)d)[0] = (-((font_data >> 7)) & xorcol) ^ bgcol;
((uint32_t *)d)[1] = (-((font_data >> 6) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[2] = (-((font_data >> 5) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[3] = (-((font_data >> 4) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[4] = (-((font_data >> 3) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[5] = (-((font_data >> 2) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[6] = (-((font_data >> 1) & 1) & xorcol) ^ bgcol;
v = (-((font_data >> 0) & 1) & xorcol) ^ bgcol;
((uint32_t *)d)[7] = v;
if (dup9)
((uint32_t *)d)[8] = v;
else
((uint32_t *)d)[8] = bgcol;
font_ptr += 4;
d += 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
*/
static void vga_draw_line2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
uint32_t plane_mask, *palette, data, v;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr);
data &= plane_mask;
v = expand2[GET_PLANE(data, 0)];
v |= expand2[GET_PLANE(data, 2)] << 2;
((uint32_t *)d)[0] = palette[v >> 12];
((uint32_t *)d)[1] = palette[(v >> 8) & 0xf];
((uint32_t *)d)[2] = palette[(v >> 4) & 0xf];
((uint32_t *)d)[3] = palette[(v >> 0) & 0xf];
v = expand2[GET_PLANE(data, 1)];
v |= expand2[GET_PLANE(data, 3)] << 2;
((uint32_t *)d)[4] = palette[v >> 12];
((uint32_t *)d)[5] = palette[(v >> 8) & 0xf];
((uint32_t *)d)[6] = palette[(v >> 4) & 0xf];
((uint32_t *)d)[7] = palette[(v >> 0) & 0xf];
d += 32;
addr += 4;
}
}
#define PUT_PIXEL2(d, n, v) \
((uint32_t *)d)[2*(n)] = ((uint32_t *)d)[2*(n)+1] = (v)
/*
* 4 color mode, dup2 horizontal
*/
static void vga_draw_line2d2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
uint32_t plane_mask, *palette, data, v;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr);
data &= plane_mask;
v = expand2[GET_PLANE(data, 0)];
v |= expand2[GET_PLANE(data, 2)] << 2;
PUT_PIXEL2(d, 0, palette[v >> 12]);
PUT_PIXEL2(d, 1, palette[(v >> 8) & 0xf]);
PUT_PIXEL2(d, 2, palette[(v >> 4) & 0xf]);
PUT_PIXEL2(d, 3, palette[(v >> 0) & 0xf]);
v = expand2[GET_PLANE(data, 1)];
v |= expand2[GET_PLANE(data, 3)] << 2;
PUT_PIXEL2(d, 4, palette[v >> 12]);
PUT_PIXEL2(d, 5, palette[(v >> 8) & 0xf]);
PUT_PIXEL2(d, 6, palette[(v >> 4) & 0xf]);
PUT_PIXEL2(d, 7, palette[(v >> 0) & 0xf]);
d += 64;
addr += 4;
}
}
/*
* 16 color mode
*/
static void vga_draw_line4(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
uint32_t plane_mask, data, v, *palette;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr);
data &= plane_mask;
v = expand4[GET_PLANE(data, 0)];
v |= expand4[GET_PLANE(data, 1)] << 1;
v |= expand4[GET_PLANE(data, 2)] << 2;
v |= expand4[GET_PLANE(data, 3)] << 3;
((uint32_t *)d)[0] = palette[v >> 28];
((uint32_t *)d)[1] = palette[(v >> 24) & 0xf];
((uint32_t *)d)[2] = palette[(v >> 20) & 0xf];
((uint32_t *)d)[3] = palette[(v >> 16) & 0xf];
((uint32_t *)d)[4] = palette[(v >> 12) & 0xf];
((uint32_t *)d)[5] = palette[(v >> 8) & 0xf];
((uint32_t *)d)[6] = palette[(v >> 4) & 0xf];
((uint32_t *)d)[7] = palette[(v >> 0) & 0xf];
d += 32;
addr += 4;
}
}
/*
* 16 color mode, dup2 horizontal
*/
static void vga_draw_line4d2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
uint32_t plane_mask, data, v, *palette;
int x;
palette = vga->last_palette;
plane_mask = mask16[vga->ar[VGA_ATC_PLANE_ENABLE] & 0xf];
width >>= 3;
for(x = 0; x < width; x++) {
data = vga_read_dword_le(vga, addr);
data &= plane_mask;
v = expand4[GET_PLANE(data, 0)];
v |= expand4[GET_PLANE(data, 1)] << 1;
v |= expand4[GET_PLANE(data, 2)] << 2;
v |= expand4[GET_PLANE(data, 3)] << 3;
PUT_PIXEL2(d, 0, palette[v >> 28]);
PUT_PIXEL2(d, 1, palette[(v >> 24) & 0xf]);
PUT_PIXEL2(d, 2, palette[(v >> 20) & 0xf]);
PUT_PIXEL2(d, 3, palette[(v >> 16) & 0xf]);
PUT_PIXEL2(d, 4, palette[(v >> 12) & 0xf]);
PUT_PIXEL2(d, 5, palette[(v >> 8) & 0xf]);
PUT_PIXEL2(d, 6, palette[(v >> 4) & 0xf]);
PUT_PIXEL2(d, 7, palette[(v >> 0) & 0xf]);
d += 64;
addr += 4;
}
}
/*
* 256 color mode, double pixels
*
* XXX: add plane_mask support (never used in standard VGA modes)
*/
static void vga_draw_line8d2(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
uint32_t *palette;
int x;
palette = vga->last_palette;
width >>= 3;
for(x = 0; x < width; x++) {
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 += 32;
addr += 4;
}
}
/*
* standard 256 color mode
*
* XXX: add plane_mask support (never used in standard VGA modes)
*/
static void vga_draw_line8(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
uint32_t *palette;
int x;
palette = vga->last_palette;
width >>= 3;
for(x = 0; x < width; x++) {
((uint32_t *)d)[0] = palette[vga_read_byte(vga, addr + 0)];
((uint32_t *)d)[1] = palette[vga_read_byte(vga, addr + 1)];
((uint32_t *)d)[2] = palette[vga_read_byte(vga, addr + 2)];
((uint32_t *)d)[3] = palette[vga_read_byte(vga, addr + 3)];
((uint32_t *)d)[4] = palette[vga_read_byte(vga, addr + 4)];
((uint32_t *)d)[5] = palette[vga_read_byte(vga, addr + 5)];
((uint32_t *)d)[6] = palette[vga_read_byte(vga, addr + 6)];
((uint32_t *)d)[7] = palette[vga_read_byte(vga, addr + 7)];
d += 32;
addr += 8;
}
}
/*
* 15 bit color
*/
static void vga_draw_line15_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_le(vga, addr);
r = (v >> 7) & 0xf8;
g = (v >> 2) & 0xf8;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
}
static void vga_draw_line15_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_be(vga, addr);
r = (v >> 7) & 0xf8;
g = (v >> 2) & 0xf8;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
}
/*
* 16 bit color
*/
static void vga_draw_line16_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_le(vga, addr);
r = (v >> 8) & 0xf8;
g = (v >> 3) & 0xfc;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
}
static void vga_draw_line16_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t v, r, g, b;
w = width;
do {
v = vga_read_word_be(vga, addr);
r = (v >> 8) & 0xf8;
g = (v >> 3) & 0xfc;
b = (v << 3) & 0xf8;
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 2;
d += 4;
} while (--w != 0);
}
/*
* 24 bit color
*/
static void vga_draw_line24_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t r, g, b;
w = width;
do {
b = vga_read_byte(vga, addr + 0);
g = vga_read_byte(vga, addr + 1);
r = vga_read_byte(vga, addr + 2);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 3;
d += 4;
} while (--w != 0);
}
static void vga_draw_line24_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t r, g, b;
w = width;
do {
r = vga_read_byte(vga, addr + 0);
g = vga_read_byte(vga, addr + 1);
b = vga_read_byte(vga, addr + 2);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 3;
d += 4;
} while (--w != 0);
}
/*
* 32 bit color
*/
static void vga_draw_line32_le(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t r, g, b;
w = width;
do {
b = vga_read_byte(vga, addr + 0);
g = vga_read_byte(vga, addr + 1);
r = vga_read_byte(vga, addr + 2);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 4;
d += 4;
} while (--w != 0);
}
static void vga_draw_line32_be(VGACommonState *vga, uint8_t *d,
uint32_t addr, int width)
{
int w;
uint32_t r, g, b;
w = width;
do {
r = vga_read_byte(vga, addr + 1);
g = vga_read_byte(vga, addr + 2);
b = vga_read_byte(vga, addr + 3);
((uint32_t *)d)[0] = rgb_to_pixel32(r, g, b);
addr += 4;
d += 4;
} while (--w != 0);
}
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