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[Qemu-devel] [PULL 2/4] cirrus: allow zero source pitch in pattern fill
From: |
Gerd Hoffmann |
Subject: |
[Qemu-devel] [PULL 2/4] cirrus: allow zero source pitch in pattern fill rops |
Date: |
Thu, 2 Feb 2017 16:05:05 +0100 |
From: Wolfgang Bumiller <address@hidden>
The rops used by cirrus_bitblt_common_patterncopy only use
the destination pitch, so the source pitch shoul allowed to
be zero and the blit with used for the range check around the
source address.
Signed-off-by: Wolfgang Bumiller <address@hidden>
Message-id: address@hidden
Signed-off-by: Gerd Hoffmann <address@hidden>
---
hw/display/cirrus_vga.c | 27 +++++++++++++++++++--------
1 file changed, 19 insertions(+), 8 deletions(-)
diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
index 0f05e45..98f089e 100644
--- a/hw/display/cirrus_vga.c
+++ b/hw/display/cirrus_vga.c
@@ -272,9 +272,6 @@ static void cirrus_update_memory_access(CirrusVGAState *s);
static bool blit_region_is_unsafe(struct CirrusVGAState *s,
int32_t pitch, int32_t addr)
{
- if (!pitch) {
- return true;
- }
if (pitch < 0) {
int64_t min = addr
+ ((int64_t)s->cirrus_blt_height-1) * pitch;
@@ -294,8 +291,11 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s,
return false;
}
-static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only)
+static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only,
+ bool zero_src_pitch_ok)
{
+ int32_t check_pitch;
+
/* should be the case, see cirrus_bitblt_start */
assert(s->cirrus_blt_width > 0);
assert(s->cirrus_blt_height > 0);
@@ -304,6 +304,10 @@ static bool blit_is_unsafe(struct CirrusVGAState *s, bool
dst_only)
return true;
}
+ if (!s->cirrus_blt_dstpitch) {
+ return true;
+ }
+
if (blit_region_is_unsafe(s, s->cirrus_blt_dstpitch,
s->cirrus_blt_dstaddr & s->cirrus_addr_mask)) {
return true;
@@ -311,7 +315,13 @@ static bool blit_is_unsafe(struct CirrusVGAState *s, bool
dst_only)
if (dst_only) {
return false;
}
- if (blit_region_is_unsafe(s, s->cirrus_blt_srcpitch,
+
+ check_pitch = s->cirrus_blt_srcpitch;
+ if (!zero_src_pitch_ok && !check_pitch) {
+ check_pitch = s->cirrus_blt_width;
+ }
+
+ if (blit_region_is_unsafe(s, check_pitch,
s->cirrus_blt_srcaddr & s->cirrus_addr_mask)) {
return true;
}
@@ -681,8 +691,9 @@ static int cirrus_bitblt_common_patterncopy(CirrusVGAState
* s,
dst = s->vga.vram_ptr + (s->cirrus_blt_dstaddr & s->cirrus_addr_mask);
- if (blit_is_unsafe(s, false))
+ if (blit_is_unsafe(s, false, true)) {
return 0;
+ }
(*s->cirrus_rop) (s, dst, src,
s->cirrus_blt_dstpitch, 0,
@@ -699,7 +710,7 @@ static int cirrus_bitblt_solidfill(CirrusVGAState *s, int
blt_rop)
{
cirrus_fill_t rop_func;
- if (blit_is_unsafe(s, true)) {
+ if (blit_is_unsafe(s, true, true)) {
return 0;
}
rop_func = cirrus_fill[rop_to_index[blt_rop]][s->cirrus_blt_pixelwidth -
1];
@@ -803,7 +814,7 @@ static int cirrus_do_copy(CirrusVGAState *s, int dst, int
src, int w, int h)
static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
{
- if (blit_is_unsafe(s, false))
+ if (blit_is_unsafe(s, false, false))
return 0;
return cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,
--
1.8.3.1
- [Qemu-devel] [PULL 4/4] cirrus: fix oob access issue (CVE-2017-2615), (continued)
- [Qemu-devel] [PULL 4/4] cirrus: fix oob access issue (CVE-2017-2615), Gerd Hoffmann, 2017/02/02
- [Qemu-devel] [PULL 1/4] cirrus: handle negative pitch in cirrus_invalidate_region(), Gerd Hoffmann, 2017/02/02
- [Qemu-devel] [PULL 3/4] cirrus: fix blit address mask handling, Gerd Hoffmann, 2017/02/02
- [Qemu-devel] [PULL 2/4] cirrus: allow zero source pitch in pattern fill rops, Gerd Hoffmann, 2017/02/02
- Re: [Qemu-devel] [PULL 0/4] cirrus: multiple bugfixes, including CVE-2017-2615 fix., Gerd Hoffmann, 2017/02/02
- [Qemu-devel] [PULL 0/4] cirrus: multiple bugfixes, including CVE-2017-2615 fix., Gerd Hoffmann, 2017/02/02
- [Qemu-devel] [PULL 4/4] cirrus: fix oob access issue (CVE-2017-2615), Gerd Hoffmann, 2017/02/02
- [Qemu-devel] [PULL 1/4] cirrus: handle negative pitch in cirrus_invalidate_region(), Gerd Hoffmann, 2017/02/02
- [Qemu-devel] [PULL 2/4] cirrus: allow zero source pitch in pattern fill rops,
Gerd Hoffmann <=
- [Qemu-devel] [PULL 3/4] cirrus: fix blit address mask handling, Gerd Hoffmann, 2017/02/02
- Re: [Qemu-devel] [PULL 0/4] cirrus: multiple bugfixes, including CVE-2017-2615 fix., Peter Maydell, 2017/02/03