From 52b7f43c8fa185ab856bcaacda7abc9a6fc07f84 Mon Sep 17 00:00:00 2001 From: Bruce Rogers Date: Tue, 21 Feb 2017 10:54:38 -0800 Subject: [PATCH 1/2] 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 --- 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 7bf3707..34a6900 100644 --- a/hw/display/cirrus_vga.c +++ b/tools/qemu-xen/hw/display/cirrus_vga.c @@ -288,7 +288,7 @@ 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); @@ -302,6 +302,9 @@ 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; @@ -667,7 +670,7 @@ 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, @@ -685,7 +688,7 @@ 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]; @@ -784,7 +787,7 @@ static void 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; cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr, -- 2.1.4