From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pablo Neira Ayuso Subject: [PATCH 12/47] netfilter: x_tables: limit allocation requests for blob rule heads Date: Fri, 30 Mar 2018 13:38:39 +0200 Message-ID: <20180330113914.18431-3-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]:49246 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751361AbeC3Ljr (ORCPT ); Fri, 30 Mar 2018 07:39:47 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id E0E229D32B for ; Fri, 30 Mar 2018 13:39:28 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id D13ADDA78B for ; Fri, 30 Mar 2018 13:39:28 +0200 (CEST) In-Reply-To: <20180330113914.18431-1-pablo@netfilter.org> Sender: netdev-owner@vger.kernel.org List-ID: From: Florian Westphal This is a very conservative limit (134217728 rules), but good enough to not trigger frequent oom from syzkaller. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso --- 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 dc68ac49614a..01f8e122e74e 100644 --- a/net/netfilter/x_tables.c +++ b/net/netfilter/x_tables.c @@ -894,6 +894,9 @@ EXPORT_SYMBOL(xt_check_entry_offsets); */ unsigned int *xt_alloc_entry_offsets(unsigned int size) { + if (size > XT_MAX_TABLE_SIZE / sizeof(unsigned int)) + return NULL; + return kvmalloc_array(size, sizeof(unsigned int), GFP_KERNEL | __GFP_ZERO); } -- 2.11.0