From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Westphal Subject: [PATCH nf] netfilter: x_tables: check for size overflow Date: Thu, 10 Mar 2016 01:56:23 +0100 Message-ID: <1457571383-25520-1-git-send-email-fw@strlen.de> Cc: hawkes@google.com, Florian Westphal To: Return-path: Received: from Chamillionaire.breakpoint.cc ([80.244.247.6]:42551 "EHLO Chamillionaire.breakpoint.cc" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934460AbcCJA4F (ORCPT ); Wed, 9 Mar 2016 19:56:05 -0500 Sender: netfilter-devel-owner@vger.kernel.org List-ID: Ben Hawkes says: integer overflow in xt_alloc_table_info, which on 32-bit systems can lead to small structure allocation and a copy_from_user based heap corruption. Reported-by: Ben Hawkes Signed-off-by: Florian Westphal --- net/netfilter/x_tables.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index c8a0b7d..17a9a9f 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -659,6 +659,9 @@ struct xt_table_info *xt_alloc_table_info(unsigned int size) struct xt_table_info *info = NULL; size_t sz = sizeof(*info) + size; + if (sz < size || sz < sizeof(*info)) + return NULL; + /* Pedantry: prevent them from hitting BUG() in vmalloc.c --RR */ if ((SMP_ALIGN(size) >> PAGE_SHIFT) + 2 > totalram_pages) return NULL; -- 2.4.10