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display: cirrus: ignore source pitch value as needed in blit_is_unsafe

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Commit 4299b90 added a check which is too broad, given that the source
pitch value is not required to be initialized for solid fill operations.
This patch refines the blit_is_unsafe() check to ignore source pitch in
that case. After applying the above commit as a security patch, we
noticed the SLES 11 SP4 guest gui failed to initialize properly.

Signed-off-by: Bruce Rogers <brogers@suse.com>
Message-id: 20170109203520.5619-1-brogers@suse.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
This commit is contained in:
Bruce Rogers 2017-01-09 13:35:20 -07:00 committed by Gerd Hoffmann
parent 85d9d04447
commit 913a87885f
1 changed files with 7 additions and 4 deletions
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11
hw/display/cirrus_vga.c
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@ -294,7 +294,7 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s,
return false; return false;
} }
static bool blit_is_unsafe(struct CirrusVGAState *s) static bool blit_is_unsafe(struct CirrusVGAState *s, bool dst_only)
{ {
/* should be the case, see cirrus_bitblt_start */ /* should be the case, see cirrus_bitblt_start */
assert(s->cirrus_blt_width > 0); assert(s->cirrus_blt_width > 0);
@ -308,6 +308,9 @@ static bool blit_is_unsafe(struct CirrusVGAState *s)
s->cirrus_blt_dstaddr & s->cirrus_addr_mask)) { s->cirrus_blt_dstaddr & s->cirrus_addr_mask)) {
return true; return true;
} }
if (dst_only) {
return false;
}
if (blit_region_is_unsafe(s, s->cirrus_blt_srcpitch, if (blit_region_is_unsafe(s, s->cirrus_blt_srcpitch,
s->cirrus_blt_srcaddr & s->cirrus_addr_mask)) { s->cirrus_blt_srcaddr & s->cirrus_addr_mask)) {
return true; return true;
@ -673,7 +676,7 @@ static int cirrus_bitblt_common_patterncopy(CirrusVGAState * s,
dst = s->vga.vram_ptr + (s->cirrus_blt_dstaddr & s->cirrus_addr_mask); dst = s->vga.vram_ptr + (s->cirrus_blt_dstaddr & s->cirrus_addr_mask);
if (blit_is_unsafe(s)) if (blit_is_unsafe(s, false))
return 0; return 0;
(*s->cirrus_rop) (s, dst, src, (*s->cirrus_rop) (s, dst, src,
@ -691,7 +694,7 @@ static int cirrus_bitblt_solidfill(CirrusVGAState *s, int blt_rop)
{ {
cirrus_fill_t rop_func; cirrus_fill_t rop_func;
if (blit_is_unsafe(s)) { if (blit_is_unsafe(s, true)) {
return 0; return 0;
} }
rop_func = cirrus_fill[rop_to_index[blt_rop]][s->cirrus_blt_pixelwidth - 1]; rop_func = cirrus_fill[rop_to_index[blt_rop]][s->cirrus_blt_pixelwidth - 1];
@ -795,7 +798,7 @@ static int cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s) static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
{ {
if (blit_is_unsafe(s)) if (blit_is_unsafe(s, false))
return 0; return 0;
return cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr, return cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,