From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54905) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1bwP5b-0000sW-DU for qemu-devel@nongnu.org; Tue, 18 Oct 2016 03:45:36 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1bwP5W-0001rb-Ne for qemu-devel@nongnu.org; Tue, 18 Oct 2016 03:45:35 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55170) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1bwP5W-0001r4-Ab for qemu-devel@nongnu.org; Tue, 18 Oct 2016 03:45:30 -0400 From: P J P Date: Tue, 18 Oct 2016 13:15:17 +0530 Message-Id: <1476776717-24807-1-git-send-email-ppandit@redhat.com> Subject: [Qemu-devel] [PATCH] display: cirrus: check vga bits per pixel(bpp) value List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Qemu Developers Cc: Peter Maydell , Huawei PSIRT , Prasad J Pandit 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 --- 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 3d712d5..bdb092e 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -272,6 +272,9 @@ 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; @@ -715,7 +718,7 @@ 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; @@ -729,6 +732,9 @@ 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 */ @@ -783,6 +789,8 @@ 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) @@ -790,11 +798,9 @@ 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; } /*************************************** -- 2.7.4