Commit 913a8788 authored by Bruce Rogers's avatar Bruce Rogers Committed by Gerd Hoffmann
Browse files

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



Commit 4299b90e 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: default avatarBruce Rogers <brogers@suse.com>
Message-id: 20170109203520.5619-1-brogers@suse.com
Signed-off-by: default avatarGerd Hoffmann <kraxel@redhat.com>
parent 85d9d044

hw/display/cirrus_vga.c

+7 −4
Original line number Diff line number Diff line
@@ -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,