From e0ec8bdaf64a147c83334ae6f59e279c4560d01b Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 7 Feb 2017 10:07:47 +0100 Subject: [PATCH 3/8] display: cirrus: check vga bits per pixel(bpp) value RH-Author: Gerd Hoffmann Message-id: <1486462072-32174-3-git-send-email-kraxel@redhat.com> Patchwork-id: 73568 O-Subject: [RHEL-7.4 qemu-kvm PATCH 2/7] display: cirrus: check vga bits per pixel(bpp) value Bugzilla: 1418232 RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: Paolo Bonzini RH-Acked-by: Miroslav Rezanina From: Prasad J Pandit In Cirrus CLGD 54xx VGA Emulator, if cirrus graphics mode is VGA, 'cirrus_get_bpp' returns zero(0), which could lead to a divide by zero error in while copying pixel data. The same could occur via blit pitch values. Add check to avoid it. Reported-by: Huawei PSIRT Signed-off-by: Prasad J Pandit Message-id: 1476776717-24807-1-git-send-email-ppandit@redhat.com Signed-off-by: Gerd Hoffmann (cherry picked from commit 4299b90e9ba9ce5ca9024572804ba751aa1a7e70) Signed-off-by: Miroslav Rezanina --- hw/display/cirrus_vga.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index c42dfcf..dacfac6 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -267,6 +267,9 @@ static void cirrus_update_memory_access(CirrusVGAState *s); static bool blit_region_is_unsafe(struct CirrusVGAState *s, int32_t pitch, int32_t addr) { + if (!pitch) { + return true; + } if (pitch < 0) { int64_t min = addr + ((int64_t)s->cirrus_blt_height-1) * pitch; @@ -710,7 +713,7 @@ static int cirrus_bitblt_videotovideo_patterncopy(CirrusVGAState * s) s->cirrus_addr_mask)); } -static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h) +static int cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h) { int sx = 0, sy = 0; int dx = 0, dy = 0; @@ -724,6 +727,9 @@ static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h) int width, height; depth = s->vga.get_bpp(&s->vga) / 8; + if (!depth) { + return 0; + } s->vga.get_resolution(&s->vga, &width, &height); /* extra x, y */ @@ -778,6 +784,8 @@ static void cirrus_do_copy(CirrusVGAState *s, int dst, int src, int w, int h) cirrus_invalidate_region(s, s->cirrus_blt_dstaddr, s->cirrus_blt_dstpitch, s->cirrus_blt_width, s->cirrus_blt_height); + + return 1; } static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s) @@ -785,11 +793,9 @@ static int cirrus_bitblt_videotovideo_copy(CirrusVGAState * s) if (blit_is_unsafe(s)) return 0; - 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, s->cirrus_blt_srcaddr - s->vga.start_addr, s->cirrus_blt_width, s->cirrus_blt_height); - - return 1; } /*************************************** -- 1.8.3.1