From 447e05bbd5a4867abea6e4a91f1f0b2ca20fdbb2 Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Tue, 25 Mar 2014 11:45:46 +0100 Subject: [PATCH 28/48] bochs: Check catalog_size header field (CVE-2014-0143) RH-Author: Kevin Wolf Message-id: <1395744364-16049-28-git-send-email-kwolf@redhat.com> Patchwork-id: n/a O-Subject: [EMBARGOED RHEL-6.6/6.5.z qemu-kvm PATCH v2 27/45] bochs: Check catalog_size header field (CVE-2014-0143) Bugzilla: 1079319 RH-Acked-by: Max Reitz RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Laszlo Ersek Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1079319 Upstream status: Embargoed It should neither become negative nor allow unbounded memory allocations. This fixes aborts in g_malloc() and an s->catalog_bitmap buffer overflow on big endian hosts. 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 | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/block/bochs.c b/block/bochs.c index c6f2cd6..36d9c47 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -121,7 +121,14 @@ static int bochs_open(BlockDriverState *bs, int flags) bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512; } + /* Limit to 1M entries to avoid unbounded allocation. This is what is + * needed for the largest image that bximage can create (~8 TB). */ s->catalog_size = le32_to_cpu(bochs.catalog); + if (s->catalog_size > 0x100000) { + qerror_report(QERR_GENERIC_ERROR, "Catalog size is too large"); + return -EFBIG; + } + s->catalog_bitmap = g_malloc(s->catalog_size * 4); ret = bdrv_pread(bs->file, le32_to_cpu(bochs.header), s->catalog_bitmap, @@ -140,6 +147,13 @@ static int bochs_open(BlockDriverState *bs, int flags) s->extent_size = le32_to_cpu(bochs.extent); + if (s->catalog_size < bs->total_sectors / s->extent_size) { + qerror_report(QERR_GENERIC_ERROR, + "Catalog size is too small for this disk size"); + ret = -EINVAL; + goto fail; + } + qemu_co_mutex_init(&s->lock); return 0; -- 1.7.1