From ca1f9cbfdce4d63b10d57de80fef89a89d92a540 Mon Sep 17 00:00:00 2001 From: Prasad J Pandit Date: Wed, 21 Oct 2020 16:08:18 +0530 Subject: [PATCH 1/1] ati: check x y display parameter values The source and destination x,y display parameters in ati_2d_blt() may run off the vga limits if either of s->regs.[src|dst]_[xy] is zero. Check the parameter values to avoid potential crash. Reported-by: Gaoning Pan Signed-off-by: Prasad J Pandit Message-id: 20201021103818.1704030-1-ppandit@redhat.com Signed-off-by: Gerd Hoffmann Upstream-Status: Backport [ https://git.qemu.org/?p=qemu.git;a=commitdiff;h=ca1f9cbfdce4d63b10d57de80fef89a89d92a540;hp=2ddafce7f797082ad216657c830afd4546f16e37 ] CVE: CVE-2020-24352 Signed-off-by: Chee Yang Lee --- hw/display/ati_2d.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/hw/display/ati_2d.c b/hw/display/ati_2d.c index 23a8ae0..4dc10ea 100644 --- a/hw/display/ati_2d.c +++ b/hw/display/ati_2d.c @@ -75,8 +75,9 @@ void ati_2d_blt(ATIVGAState *s) dst_stride *= bpp; } uint8_t *end = s->vga.vram_ptr + s->vga.vram_size; - if (dst_bits >= end || dst_bits + dst_x + (dst_y + s->regs.dst_height) * - dst_stride >= end) { + if (dst_x > 0x3fff || dst_y > 0x3fff || dst_bits >= end + || dst_bits + dst_x + + (dst_y + s->regs.dst_height) * dst_stride >= end) { qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n"); return; } @@ -107,8 +108,9 @@ void ati_2d_blt(ATIVGAState *s) src_bits += s->regs.crtc_offset & 0x07ffffff; src_stride *= bpp; } - if (src_bits >= end || src_bits + src_x + - (src_y + s->regs.dst_height) * src_stride >= end) { + if (src_x > 0x3fff || src_y > 0x3fff || src_bits >= end + || src_bits + src_x + + (src_y + s->regs.dst_height) * src_stride >= end) { qemu_log_mask(LOG_UNIMP, "blt outside vram not implemented\n"); return; } -- 1.8.3.1