From patchwork Wed Mar 26 12:05:33 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stefan Hajnoczi X-Patchwork-Id: 333893 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 0D91714008D for ; Thu, 27 Mar 2014 00:23:32 +1100 (EST) Received: from localhost ([::1]:47425 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSmgw-0007Er-Jh for incoming@patchwork.ozlabs.org; Wed, 26 Mar 2014 08:12:22 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:49894) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSmbP-0000ms-WD for qemu-devel@nongnu.org; Wed, 26 Mar 2014 08:06:45 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WSmbK-0003vE-0o for qemu-devel@nongnu.org; Wed, 26 Mar 2014 08:06:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:50227) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WSmbJ-0003uv-Ps; Wed, 26 Mar 2014 08:06:33 -0400 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s2QC6W1k031522 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 26 Mar 2014 08:06:32 -0400 Received: from localhost (dhcp-64-106.muc.redhat.com [10.32.64.106]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id s2QC6V8E014362; Wed, 26 Mar 2014 08:06:32 -0400 From: Stefan Hajnoczi To: Date: Wed, 26 Mar 2014 13:05:33 +0100 Message-Id: <1395835569-21193-12-git-send-email-stefanha@redhat.com> In-Reply-To: <1395835569-21193-1-git-send-email-stefanha@redhat.com> References: <1395835569-21193-1-git-send-email-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.23 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Kevin Wolf , pmatouse@redhat.com, qemu-stable@nongnu.org Subject: [Qemu-devel] [PATCH for-2.0 11/47] bochs: Check catalog_size header field (CVE-2014-0143) X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org From: Kevin Wolf 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 Reviewed-by: Max Reitz --- block/bochs.c | 13 +++++++++++++ tests/qemu-iotests/078 | 13 +++++++++++++ tests/qemu-iotests/078.out | 10 +++++++++- 3 files changed, 35 insertions(+), 1 deletion(-) diff --git a/block/bochs.c b/block/bochs.c index e923eed..0ffa9c1 100644 --- a/block/bochs.c +++ b/block/bochs.c @@ -123,7 +123,14 @@ static int bochs_open(BlockDriverState *bs, QDict *options, 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) { + error_setg(errp, "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, @@ -142,6 +149,12 @@ static int bochs_open(BlockDriverState *bs, QDict *options, int flags, s->extent_size = le32_to_cpu(bochs.extent); + if (s->catalog_size < bs->total_sectors / s->extent_size) { + error_setg(errp, "Catalog size is too small for this disk size"); + ret = -EINVAL; + goto fail; + } + qemu_co_mutex_init(&s->lock); return 0; diff --git a/tests/qemu-iotests/078 b/tests/qemu-iotests/078 index 73b573a..902ef0f 100755 --- a/tests/qemu-iotests/078 +++ b/tests/qemu-iotests/078 @@ -43,6 +43,7 @@ _supported_proto generic _supported_os Linux catalog_size_offset=$((0x48)) +disk_size_offset=$((0x58)) echo echo "== Read from a valid image ==" @@ -55,6 +56,18 @@ _use_sample_img empty.bochs.bz2 poke_file "$TEST_IMG" "$catalog_size_offset" "\xff\xff\xff\xff" { $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir +echo +echo "== Overflow for catalog size * sizeof(uint32_t) ==" +_use_sample_img empty.bochs.bz2 +poke_file "$TEST_IMG" "$catalog_size_offset" "\x00\x00\x00\x40" +{ $QEMU_IO -c "read 0 512" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir + +echo +echo "== Too small catalog bitmap for image size ==" +_use_sample_img empty.bochs.bz2 +poke_file "$TEST_IMG" "$disk_size_offset" "\x00\xc0\x0f\x00\x00\x00\x00\x7f" +{ $QEMU_IO -c "read 2T 4k" $TEST_IMG; } 2>&1 | _filter_qemu_io | _filter_testdir + # success, all done echo "*** done" rm -f $seq.full diff --git a/tests/qemu-iotests/078.out b/tests/qemu-iotests/078.out index ef8c42d..7254693 100644 --- a/tests/qemu-iotests/078.out +++ b/tests/qemu-iotests/078.out @@ -5,6 +5,14 @@ read 512/512 bytes at offset 0 512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec) == Negative catalog size == -qemu-io: can't open device TEST_DIR/empty.bochs: Could not open 'TEST_DIR/empty.bochs': Interrupted system call +qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too large +no file open, try 'help open' + +== Overflow for catalog size * sizeof(uint32_t) == +qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too large +no file open, try 'help open' + +== Too small catalog bitmap for image size == +qemu-io: can't open device TEST_DIR/empty.bochs: Catalog size is too small for this disk size no file open, try 'help open' *** done