From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34668) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoUTp-0007EZ-Ap for qemu-devel@nongnu.org; Wed, 12 Nov 2014 04:44:55 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1XoUTi-00085M-CL for qemu-devel@nongnu.org; Wed, 12 Nov 2014 04:44:49 -0500 Received: from mx1.redhat.com ([209.132.183.28]:48885) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1XoUTi-00085F-5j for qemu-devel@nongnu.org; Wed, 12 Nov 2014 04:44:42 -0500 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 sAC9if1X025961 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Wed, 12 Nov 2014 04:44:41 -0500 Date: Wed, 12 Nov 2014 11:44:39 +0200 From: "Michael S. Tsirkin" Message-ID: <1415785203-26938-2-git-send-email-mst@redhat.com> References: <1415785203-26938-1-git-send-email-mst@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1415785203-26938-1-git-send-email-mst@redhat.com> Subject: [Qemu-devel] [PATCH 1/4] migration: fix parameter validation on ram load List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: dgilbert@redhat.com, Juan Quintela During migration, the values read from migration stream during ram load are not validated. Especially offset in host_from_stream_offset() and also the length of the writes in the callers of said function. To fix this, we need to make sure that the [offset, offset + length] range fits into one of the allocated memory regions. Validating addr < len should be sufficient since data seems to always be managed in TARGET_PAGE_SIZE chunks. Fixes: CVE-2014-7840 Note: follow-up patches add extra checks on each block->host access. Signed-off-by: Michael S. Tsirkin --- arch_init.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch_init.c b/arch_init.c index 88a5ba0..593a990 100644 --- a/arch_init.c +++ b/arch_init.c @@ -1006,7 +1006,7 @@ static inline void *host_from_stream_offset(QEMUFile *f, uint8_t len; if (flags & RAM_SAVE_FLAG_CONTINUE) { - if (!block) { + if (!block || block->length <= offset) { error_report("Ack, bad migration stream!"); return NULL; } @@ -1019,8 +1019,9 @@ static inline void *host_from_stream_offset(QEMUFile *f, id[len] = 0; QTAILQ_FOREACH(block, &ram_list.blocks, next) { - if (!strncmp(id, block->idstr, sizeof(id))) + if (!strncmp(id, block->idstr, sizeof(id)) && block->length > offset) { return memory_region_get_ram_ptr(block->mr) + offset; + } } error_report("Can't find block %s!", id); -- MST