From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:52660 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753525Ab3JGVnQ (ORCPT ); Mon, 7 Oct 2013 17:43:16 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r97LhGaw017186 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Mon, 7 Oct 2013 17:43:16 -0400 From: Zach Brown To: linux-btrfs@vger.kernel.org, Eric Sandeen Subject: [PATCH 04/12] btrfs-progs: don't overflow read buffer in image Date: Mon, 7 Oct 2013 14:42:57 -0700 Message-Id: <1381182185-10896-5-git-send-email-zab@redhat.com> In-Reply-To: <1381182185-10896-1-git-send-email-zab@redhat.com> References: <1381182185-10896-1-git-send-email-zab@redhat.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: search_for_chunk_blocks() allocates a fixed-size buffer and then reads arbitrary u32 sized buffers in to it. Instead let's fail if the item is bigger than the buffer. This was found by static analysis. Signed-off-by: Zach Brown --- btrfs-image.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/btrfs-image.c b/btrfs-image.c index 7474642..03ad4e9 100644 --- a/btrfs-image.c +++ b/btrfs-image.c @@ -2011,6 +2011,7 @@ static int search_for_chunk_blocks(struct mdrestore_struct *mdres, u64 current_cluster = cluster_bytenr, bytenr; u64 item_bytenr; u32 bufsize, nritems, i; + u32 max_size = MAX_PENDING_SIZE * 2; u8 *buffer, *tmp = NULL; int ret = 0; @@ -2020,7 +2021,7 @@ static int search_for_chunk_blocks(struct mdrestore_struct *mdres, return -ENOMEM; } - buffer = malloc(MAX_PENDING_SIZE * 2); + buffer = malloc(max_size); if (!buffer) { fprintf(stderr, "Error allocing buffer\n"); free(cluster); @@ -2028,7 +2029,7 @@ static int search_for_chunk_blocks(struct mdrestore_struct *mdres, } if (mdres->compress_method == COMPRESS_ZLIB) { - tmp = malloc(MAX_PENDING_SIZE * 2); + tmp = malloc(max_size); if (!tmp) { fprintf(stderr, "Error allocing tmp buffer\n"); free(cluster); @@ -2079,6 +2080,13 @@ static int search_for_chunk_blocks(struct mdrestore_struct *mdres, bufsize = le32_to_cpu(item->size); item_bytenr = le64_to_cpu(item->bytenr); + if (bufsize > max_size) { + fprintf(stderr, "item %u size %u too big\n", + i, bufsize); + ret = -EIO; + break; + } + if (mdres->compress_method == COMPRESS_ZLIB) { ret = fread(tmp, bufsize, 1, mdres->in); if (ret != 1) { @@ -2088,7 +2096,7 @@ static int search_for_chunk_blocks(struct mdrestore_struct *mdres, break; } - size = MAX_PENDING_SIZE * 2; + size = max_size; ret = uncompress(buffer, (unsigned long *)&size, tmp, bufsize); -- 1.7.11.7