From: Bruce Rogers Date: Mon, 9 Jan 2017 13:35:20 -0700 Subject: [PATCH] display: cirrus: ignore source pitch value as needed in blit_is_unsafe 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 Message-id: 20170109203520.5619-1-brogers@suse.com Signed-off-by: Gerd Hoffmann (cherry picked from commit 913a87885f589d263e682c2eb6637c6e14538061) --- hw/display/cirrus_vga.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index bdb092e..379910d 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -294,7 +294,7 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s, 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 */ 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)) { return true; } + if (dst_only) { + return false; + } if (blit_region_is_unsafe(s, s->cirrus_blt_srcpitch, s->cirrus_blt_srcaddr & s->cirrus_addr_mask)) { 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); - if (blit_is_unsafe(s)) + if (blit_is_unsafe(s, false)) return 0; (*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; - if (blit_is_unsafe(s)) { + if (blit_is_unsafe(s, true)) { return 0; } 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) { - if (blit_is_unsafe(s)) + if (blit_is_unsafe(s, false)) return 0; return cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,