1 From 9ec3cbedab41f93d2fbf742f2ca6705c2d68c3e1 Mon Sep 17 00:00:00 2001
2 From: Prasad J Pandit <pjp@fedoraproject.org>
3 Date: Tue, 18 Oct 2016 13:15:17 +0530
4 Subject: [PATCH 12/12] display: cirrus: check vga bits per pixel(bpp) value
6 In Cirrus CLGD 54xx VGA Emulator, if cirrus graphics mode is VGA,
7 'cirrus_get_bpp' returns zero(0), which could lead to a divide
8 by zero error in while copying pixel data. The same could occur
9 via blit pitch values. Add check to avoid it.
11 Reported-by: Huawei PSIRT <psirt@huawei.com>
12 Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
13 Message-id: 1476776717-24807-1-git-send-email-ppandit@redhat.com
14 Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
21 hw/display/cirrus_vga.c | 14 ++++++++++----
22 1 file changed, 10 insertions(+), 4 deletions(-)
24 diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c
25 index 3d712d5..bdb092e 100644
26 --- a/hw/display/cirrus_vga.c
27 +++ b/hw/display/cirrus_vga.c
28 @@ -272,6 +272,9 @@ static void cirrus_update_memory_access(CirrusVGAState *s);
29 static bool blit_region_is_unsafe(struct CirrusVGAState *s,
30 int32_t pitch, int32_t addr)
37 + ((int64_t)s->cirrus_blt_height-1) * pitch;
38 @@ -715,7 +718,7 @@ static int cirrus_bitblt_videotovideo_patterncopy(CirrusVGAState * s)
39 s->cirrus_addr_mask));
42 -static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
43 +static int cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
47 @@ -729,6 +732,9 @@ static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
50 depth = s->vga.get_bpp(&s->vga) / 8;
54 s->vga.get_resolution(&s->vga, &width, &height);
57 @@ -783,6 +789,8 @@ static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h)
58 cirrus_invalidate_region(s, s->cirrus_blt_dstaddr,
59 s->cirrus_blt_dstpitch, s->cirrus_blt_width,
60 s->cirrus_blt_height);
65 static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
66 @@ -790,11 +798,9 @@ static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s)
67 if (blit_is_unsafe(s))
70 - cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,
71 + return cirrus_do_copy(s, s->cirrus_blt_dstaddr - s->vga.start_addr,
72 s->cirrus_blt_srcaddr - s->vga.start_addr,
73 s->cirrus_blt_width, s->cirrus_blt_height);
78 /***************************************