From mboxrd@z Thu Jan 1 00:00:00 1970 From: Xi Wang Subject: [PATCH 3/3] libceph: fix overflow in osdmap_apply_incremental() Date: Sun, 29 Apr 2012 02:59:25 -0400 Message-ID: <1335682765-1643-3-git-send-email-xi.wang@gmail.com> References: <1335682765-1643-1-git-send-email-xi.wang@gmail.com> Return-path: Received: from mail-qa0-f53.google.com ([209.85.216.53]:43186 "EHLO mail-qa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682Ab2D2HBG (ORCPT ); Sun, 29 Apr 2012 03:01:06 -0400 Received: by qadc11 with SMTP id c11so968456qad.19 for ; Sun, 29 Apr 2012 00:01:06 -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 On 32-bit systems, a large `pglen' would overflow `pglen*sizeof(u32)' and bypass the check ceph_decode_need(p, end, pglen*sizeof(u32), bad). It would also overflow the subsequent kmalloc() size, leading to out-of-bounds write. Signed-off-by: Xi Wang --- net/ceph/osdmap.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-) diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c index 774eac6..b1ea6d1 100644 --- a/net/ceph/osdmap.c +++ b/net/ceph/osdmap.c @@ -891,6 +891,10 @@ struct ceph_osdmap *osdmap_apply_incremental(void **p, void *end, if (pglen) { /* insert */ + if (pglen > (UINT_MAX - sizeof(*pg)) / sizeof(u32)) { + err = -EINVAL; + goto bad; + } ceph_decode_need(p, end, pglen*sizeof(u32), bad); pg = kmalloc(sizeof(*pg) + sizeof(u32)*pglen, GFP_NOFS); if (!pg) { -- 1.7.5.4