From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39014) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cVxUh-0001N1-8G for qemu-devel@nongnu.org; Tue, 24 Jan 2017 04:34:31 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cVxUc-0007TX-8S for qemu-devel@nongnu.org; Tue, 24 Jan 2017 04:34:27 -0500 Received: from mail-io0-x241.google.com ([2607:f8b0:4001:c06::241]:33092) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cVxUc-0007T6-3i for qemu-devel@nongnu.org; Tue, 24 Jan 2017 04:34:22 -0500 Received: by mail-io0-x241.google.com with SMTP id 101so9672565iom.0 for ; Tue, 24 Jan 2017 01:34:20 -0800 (PST) Message-ID: <58871f9b.d635240a.4cda6.5322@mx.google.com> From: Li Qiang Date: Tue, 24 Jan 2017 01:34:07 -0800 Subject: [Qemu-devel] [PATCH] cirrus: fix oob access issue List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, ghoffman@redhat.com Cc: liqiang6-s@360.cn From: Li Qiang When doing bitblt copy in backward mode, minus the blt width first to avoid an oob access issue. Signed-off-by: Li Qiang --- hw/display/cirrus_vga.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index 379910d..7ddd289 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -277,7 +277,8 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s, } if (pitch < 0) { int64_t min = addr - + ((int64_t)s->cirrus_blt_height-1) * pitch; + + ((int64_t)s->cirrus_blt_height-1) * pitch + - s->cirrus_blt_width; int32_t max = addr + s->cirrus_blt_width; if (min < 0 || max > s->vga.vram_size) { -- 1.8.3.1