From mboxrd@z Thu Jan 1 00:00:00 1970 From: vlad@dumitrescu.ro Subject: [PATCH iproute2] lib/libnetlink: fix response seq check Date: Fri, 28 Sep 2018 13:13:39 -0400 Message-ID: <20180928171339.4332-1-vlad@dumitrescu.ro> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: chrism@mellanox.com, netdev@vger.kernel.org, maheshb@google.com, Vlad Dumitrescu To: stephen@networkplumber.org Return-path: Received: from mail-pg1-f196.google.com ([209.85.215.196]:41483 "EHLO mail-pg1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726473AbeI1XjW (ORCPT ); Fri, 28 Sep 2018 19:39:22 -0400 Received: by mail-pg1-f196.google.com with SMTP id z3-v6so4912525pgv.8 for ; Fri, 28 Sep 2018 10:14:38 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: From: Vlad Dumitrescu Taking a one-iovec example, with rtnl->seq at 42. iovlen == 1, seq becomes 43 on line 604, and a message is sent with nlmsg_seq == 43. If a response with nlmsg_seq of 42 is received, the condition being fixed in this patch would incorrectly accept it. Fixes: 72a2ff3916e5 ("lib/libnetlink: Add a new function rtnl_talk_iov") Signed-off-by: Vlad Dumitrescu --- lib/libnetlink.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/libnetlink.c b/lib/libnetlink.c index f18dceac..4d2416bf 100644 --- a/lib/libnetlink.c +++ b/lib/libnetlink.c @@ -647,7 +647,7 @@ static int __rtnl_talk_iov(struct rtnl_handle *rtnl, struct iovec *iov, if (nladdr.nl_pid != 0 || h->nlmsg_pid != rtnl->local.nl_pid || - h->nlmsg_seq > seq || h->nlmsg_seq < seq - iovlen) { + h->nlmsg_seq > seq || h->nlmsg_seq < seq - iovlen + 1) { /* Don't forget to skip that message. */ status -= NLMSG_ALIGN(len); h = (struct nlmsghdr *)((char *)h + NLMSG_ALIGN(len)); -- 2.19.0.605.g01d371f741-goog