From 9e8a16ac264276732d1b1b1c71fdb0fcd60901d3 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Tue, 25 Mar 2014 11:45:47 +0100 Subject: [PATCH 29/48] bochs: Check extent_size header field (CVE-2014-0142) RH-Author: Kevin Wolf Message-id: <1395744364-16049-29-git-send-email-kwolf@redhat.com> Patchwork-id: n/a O-Subject: [EMBARGOED RHEL-6.6/6.5.z qemu-kvm PATCH v2 28/45] bochs: Check extent_size header field (CVE-2014-0142) Bugzilla: 1079314 RH-Acked-by: Max Reitz RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Laszlo Ersek Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079314 Upstream status: Embargoed This fixes two possible division by zero crashes: In bochs_open() and in seek_to_sector(). Signed-off-by: Kevin Wolf Reviewed-by: Stefan Hajnoczi Conflicts: tests/qemu-iotests/078 tests/qemu-iotests/078.out Signed-off-by: Kevin Wolf --- block/bochs.c | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-) diff --git a/block/bochs.c b/block/bochs.c index 36d9c47..933dffe 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -146,6 +146,13 @@ static int bochs_open(BlockDriverState *bs, int flags) s->extent_blocks = 1 + (le32_to_cpu(bochs.extent) - 1) / 512; s->extent_size = le32_to_cpu(bochs.extent); + if (s->extent_size == 0) { + qerror_report(QERR_GENERIC_ERROR, "Extent size may not be zero"); + return -EINVAL; + } else if (s->extent_size > 0x800000) { + qerror_report(QERR_GENERIC_ERROR, "Extent size is too large"); + return -EINVAL; + } if (s->catalog_size < bs->total_sectors / s->extent_size) { qerror_report(QERR_GENERIC_ERROR, -- 1.7.1