From 50a34d087127807b5b8b0eb1163be9f3913efb0b Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 7 Feb 2017 09:38:20 +0100 Subject: [PATCH 9/9] cirrus: fix oob access issue (CVE-2017-2615) RH-Author: Gerd Hoffmann Message-id: <1486460300-15556-7-git-send-email-kraxel@redhat.com> Patchwork-id: 73558 O-Subject: [RHEL-7.3.z qemu-kvm-rhev PATCH 6/6] cirrus: fix oob access issue (CVE-2017-2615) Bugzilla: 1418234 RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: Laurent Vivier RH-Acked-by: Paolo Bonzini From: Li Qiang When doing bitblt copy in backward mode, we should minus the blt width first just like the adding in the forward mode. This can avoid the oob access of the front of vga's vram. Signed-off-by: Li Qiang { kraxel: with backward blits (negative pitch) addr is the topmost address, so check it as-is against vram size ] Cc: qemu-stable@nongnu.org Cc: P J P Cc: Laszlo Ersek Cc: Paolo Bonzini Cc: Wolfgang Bumiller Fixes: d3532a0db02296e687711b8cdc7791924efccea0 (CVE-2014-8106) Signed-off-by: Gerd Hoffmann Message-id: 1485938101-26602-1-git-send-email-kraxel@redhat.com Reviewed-by: Laszlo Ersek (cherry picked from commit 62d4c6bd5263bb8413a06c80144fc678df6dfb64) Signed-off-by: Miroslav Rezanina --- hw/display/cirrus_vga.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/hw/display/cirrus_vga.c b/hw/display/cirrus_vga.c index 3d1a1bd..18e065c 100644 --- a/hw/display/cirrus_vga.c +++ b/hw/display/cirrus_vga.c @@ -274,10 +274,9 @@ static bool blit_region_is_unsafe(struct CirrusVGAState *s, { if (pitch < 0) { int64_t min = addr - + ((int64_t)s->cirrus_blt_height-1) * pitch; - int32_t max = addr - + s->cirrus_blt_width; - if (min < 0 || max > s->vga.vram_size) { + + ((int64_t)s->cirrus_blt_height - 1) * pitch + - s->cirrus_blt_width; + if (min < -1 || addr >= s->vga.vram_size) { return true; } } else { -- 1.8.3.1