From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xi Wang Subject: [PATCH v2 1/3] libceph: fix overflow in __decode_pool_names() Date: Sun, 29 Apr 2012 03:07:12 -0400 Message-ID: <4F9CE8A0.80306@gmail.com> References: <1335682765-1643-1-git-send-email-xi.wang@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-iy0-f174.google.com ([209.85.210.174]:58898 "EHLO mail-iy0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682Ab2D2HHQ (ORCPT ); Sun, 29 Apr 2012 03:07:16 -0400 Received: by iadi9 with SMTP id i9so2816223iad.19 for ; Sun, 29 Apr 2012 00:07:15 -0700 (PDT) In-Reply-To: <1335682765-1643-1-git-send-email-xi.wang@gmail.com> Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Alex Elder , Sage Weil Cc: ceph-devel@vger.kernel.org, Xi Wang `len' is read from network and thus needs validation. Otherwise a large `len' would cause out-of-bounds access via the memcpy() call. In addition, len = 0xffffffff would overflow the kmalloc() size, leading to out-of-bounds write. This patch adds a check of `len' via ceph_decode_need(). Also use kstrndup rather than kmalloc/memcpy. Signed-off-by: Xi Wang --- Subject corrected. Sorry, my bad. --- net/ceph/osdmap.c | 9 +++------ 1 files changed, 3 insertions(+), 6 deletions(-) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index 29ad46e..f80afc3 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -495,15 +495,12 @@ static int __decode_pool_names(void **p, void *end, struct ceph_osdmap *map) ceph_decode_32_safe(p, end, pool, bad); ceph_decode_32_safe(p, end, len, bad); dout(" pool %d len %d\n", pool, len); + ceph_decode_need(p, end, len, bad); pi = __lookup_pg_pool(&map->pg_pools, pool); if (pi) { kfree(pi->name); - pi->name = kmalloc(len + 1, GFP_NOFS); - if (pi->name) { - memcpy(pi->name, *p, len); - pi->name[len] = '\0'; - dout(" name is %s\n", pi->name); - } + pi->name = kstrndup(*p, len, GFP_NOFS); + dout(" name is %s\n", pi->name); } *p += len; } -- 1.7.5.4