From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] netlink: Fix netlink_recvmsg() handling of error from netlink_dump(). Date: Mon, 07 Jul 2014 19:37:35 -0700 (PDT) Message-ID: <20140707.193735.766947638929765410.davem@davemloft.net> References: <1404167704-22408-1-git-send-email-blp@nicira.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org To: blp@nicira.com Return-path: Received: from shards.monkeyblade.net ([149.20.54.216]:48369 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751704AbaGHChg (ORCPT ); Mon, 7 Jul 2014 22:37:36 -0400 In-Reply-To: <1404167704-22408-1-git-send-email-blp@nicira.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Ben Pfaff Date: Mon, 30 Jun 2014 15:35:04 -0700 > netlink_dump() returns a negative errno value on error. Until now, > netlink_recvmsg() directly recorded that negative value in sk->sk_err, > but that's wrong since sk_err takes positive errno values. (This manifests > as userspace receiving a positive return value from the recv() system call, > falsely indicating success.) > > This bug was introduced in the commit that started checking the > netlink_dump() return value, commit b44d211 (netlink: handle errors from > netlink_dump()). > > Multithreaded Netlink dumps are one way to trigger this behavior in > practice, as described in the commit message for the userspace workaround > posted here: > http://openvswitch.org/pipermail/dev/2014-June/042339.html > > Signed-off-by: Ben Pfaff There's another place, later in this file, doing the same exact thing. Please respin this patch, fixing that location too. Thanks.