Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753902Ab1CJSMY (ORCPT ); Thu, 10 Mar 2011 13:12:24 -0500 Received: from mail-bw0-f46.google.com ([209.85.214.46]:48933 "EHLO mail-bw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752030Ab1CJSMV (ORCPT ); Thu, 10 Mar 2011 13:12:21 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:from:to:cc:subject:date:message-id:x-mailer; b=PIAT7OtB2zqNI91KYKucKUh8W07z8Oy7VPLGIvDog5ZIJfbAR+ORzYddVpLYl90HIA wxiGdoLVNLtAlt165mxWifKzBNq7Xr2seoZWR1n5S/36FMIJ5vmZ9VjAp4XLF1ODyaWy eVa+9naYekNKdRNY8lpWHueVQ31MCHJuvGvkk= From: Vasiliy Kulikov To: linux-kernel@vger.kernel.org Cc: security@kernel.org, Patrick McHardy , "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , netfilter-devel@vger.kernel.org, netfilter@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org Subject: [PATCH] ipv4: netfilter: ip_tables: fix infoleak to userspace Date: Thu, 10 Mar 2011 21:12:14 +0300 Message-Id: <1299780735-32607-1-git-send-email-segoon@openwall.com> X-Mailer: git-send-email 1.7.0.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1940 Lines: 54 Structures ipt_replace, compat_ipt_replace, and xt_get_revision are copied from userspace. Fields of these structs that are zero-terminated strings are not checked. When they are used as argument to a format string containing "%s" in request_module(), some sensitive information is leaked to userspace via argument of spawned modprobe process. The first and the third bugs were introduced before the git epoch; the second was introduced in 2722971c (v2.6.17-rc1). To trigger the bug one should have CAP_NET_ADMIN. Signed-off-by: Vasiliy Kulikov --- Compile tested. net/ipv4/netfilter/ip_tables.c | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-) diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c index ef7d7b9..b09ed0d 100644 --- a/net/ipv4/netfilter/ip_tables.c +++ b/net/ipv4/netfilter/ip_tables.c @@ -1262,6 +1262,7 @@ do_replace(struct net *net, const void __user *user, unsigned int len) /* overflow check */ if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); if (!newinfo) @@ -1807,6 +1808,7 @@ compat_do_replace(struct net *net, void __user *user, unsigned int len) return -ENOMEM; if (tmp.num_counters >= INT_MAX / sizeof(struct xt_counters)) return -ENOMEM; + tmp.name[sizeof(tmp.name)-1] = 0; newinfo = xt_alloc_table_info(tmp.size); if (!newinfo) @@ -2036,6 +2038,7 @@ do_ipt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) ret = -EFAULT; break; } + rev.name[sizeof(rev.name)-1] = 0; if (cmd == IPT_SO_GET_REVISION_TARGET) target = 1; -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/