Merge remote-tracking branch 'remotes/kraxel/tags/pull-cve-2014-8106-20141204-1' into staging
cirrus: fix blit region check
# gpg: Signature made Thu 04 Dec 2014 11:54:57 GMT using RSA key ID D3E87138
# gpg: Good signature from "Gerd Hoffmann (work) <kraxel@redhat.com>"
# gpg: aka "Gerd Hoffmann <gerd@kraxel.org>"
# gpg: aka "Gerd Hoffmann (private) <kraxel@gmail.com>"
* remotes/kraxel/tags/pull-cve-2014-8106-20141204-1:
cirrus: don't overflow CirrusVGAState->cirrus_bltbuf
cirrus: fix blit region check
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index 8a5b76c..2725264 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -173,20 +173,6 @@
#define CIRRUS_PNPMMIO_SIZE 0x1000
-#define BLTUNSAFE(s) \
- ( \
- ( /* check dst is within bounds */ \
- (s)->cirrus_blt_height * ABS((s)->cirrus_blt_dstpitch) \
- + ((s)->cirrus_blt_dstaddr & (s)->cirrus_addr_mask) > \
- (s)->vga.vram_size \
- ) || \
- ( /* check src is within bounds */ \
- (s)->cirrus_blt_height * ABS((s)->cirrus_blt_srcpitch) \
- + ((s)->cirrus_blt_srcaddr & (s)->cirrus_addr_mask) > \
- (s)->vga.vram_size \
- ) \
- )
-
struct CirrusVGAState;
typedef void (*cirrus_bitblt_rop_t) (struct CirrusVGAState *s,
uint8_t * dst, const uint8_t * src,
@@ -279,6 +265,50 @@
*
***************************************/
+static bool blit_region_is_unsafe(struct CirrusVGAState *s,
+ int32_t pitch, int32_t addr)
+{
+ if (pitch < 0) {
+ int64_t min = addr
+ + ((int64_t)s->cirrus_blt_height-1) * pitch;
+ int32_t max = addr
+ + s->cirrus_blt_width;
+ if (min < 0 || max >= s->vga.vram_size) {
+ return true;
+ }
+ } else {
+ int64_t max = addr
+ + ((int64_t)s->cirrus_blt_height-1) * pitch
+ + s->cirrus_blt_width;
+ if (max >= s->vga.vram_size) {
+ return true;
+ }
+ }
+ return false;
+}
+
+static bool blit_is_unsafe(struct CirrusVGAState *s)
+{
+ /* should be the case, see cirrus_bitblt_start */
+ assert(s->cirrus_blt_width > 0);
+ assert(s->cirrus_blt_height > 0);
+
+ if (s->cirrus_blt_width > CIRRUS_BLTBUFSIZE) {
+ return true;
+ }
+
+ if (blit_region_is_unsafe(s, s->cirrus_blt_dstpitch,
+ s->cirrus_blt_dstaddr & s->cirrus_addr_mask)) {
+ return true;
+ }
+ if (blit_region_is_unsafe(s, s->cirrus_blt_srcpitch,
+ s->cirrus_blt_srcaddr & s->cirrus_addr_mask)) {
+ return true;
+ }
+
+ return false;
+}
+
static void cirrus_bitblt_rop_nop(CirrusVGAState *s,
uint8_t *dst,const uint8_t *src,
int dstpitch,int srcpitch,
@@ -636,7 +666,7 @@
dst = s->vga.vram_ptr + (s->cirrus_blt_dstaddr & s->cirrus_addr_mask);
- if (BLTUNSAFE(s))
+ if (blit_is_unsafe(s))
return 0;
(*s->cirrus_rop) (s, dst, src,
@@ -654,8 +684,9 @@
{
cirrus_fill_t rop_func;
- if (BLTUNSAFE(s))
+ if (blit_is_unsafe(s)) {
return 0;
+ }
rop_func = cirrus_fill[rop_to_index[blt_rop]][s->cirrus_blt_pixelwidth - 1];
rop_func(s, s->vga.vram_ptr + (s->cirrus_blt_dstaddr & s->cirrus_addr_mask),
s->cirrus_blt_dstpitch,
@@ -752,7 +783,7 @@
static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
{
- if (BLTUNSAFE(s))
+ if (blit_is_unsafe(s))
return 0;
cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,
