From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xi Wang Subject: [PATCH 1/3] ligceph: fix overflow in __decode_pool_names() Date: Sun, 29 Apr 2012 02:59:23 -0400 Message-ID: <1335682765-1643-1-git-send-email-xi.wang@gmail.com> Return-path: Received: from mail-qa0-f46.google.com ([209.85.216.46]:50911 "EHLO mail-qa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751561Ab2D2HBD (ORCPT ); Sun, 29 Apr 2012 03:01:03 -0400 Received: by qatm19 with SMTP id m19so988683qat.19 for ; Sun, 29 Apr 2012 00:01:03 -0700 (PDT) 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 --- 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