From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 11/47] netfilter: x_tables: cap allocations at 512 mbyte Date: Fri, 30 Mar 2018 13:38:38 +0200 Message-ID: <20180330113914.18431-2-pablo@netfilter.org> References: <20180330113914.18431-1-pablo@netfilter.org> Cc: davem@davemloft.net, netdev@vger.kernel.org To: netfilter-devel@vger.kernel.org Return-path: Received: from mail.us.es ([193.147.175.20]:49232 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751337AbeC3Ljo (ORCPT ); Fri, 30 Mar 2018 07:39:44 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 2488D9D334 for ; Fri, 30 Mar 2018 13:39:26 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 16712DA729 for ; Fri, 30 Mar 2018 13:39:26 +0200 (CEST) In-Reply-To: <20180330113914.18431-1-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Florian Westphal Arbitrary limit, however, this still allows huge rulesets (> 1 million rules). This helps with automated fuzzer as it prevents oom-killer invocation. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- net/netfilter/x_tables.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/netfilter/x_tables.c b/net/netfilter/x_tables.c index 4e6cbb38e616..dc68ac49614a 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -40,6 +40,7 @@ MODULE_AUTHOR("Harald Welte "); MODULE_DESCRIPTION("{ip,ip6,arp,eb}_tables backend module"); #define XT_PCPU_BLOCK_SIZE 4096 +#define XT_MAX_TABLE_SIZE (512 * 1024 * 1024) struct compat_delta { unsigned int offset; /* offset in kernel */ @@ -1117,7 +1118,7 @@ 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 < sizeof(*info)) + if (sz < sizeof(*info) || sz >= XT_MAX_TABLE_SIZE) return NULL; /* __GFP_NORETRY is not fully supported by kvmalloc but it should -- 2.11.0