From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sabrina Dubroca Subject: Re: Regression with 5dcd8400884c ("macsec: missing dev_put() on error in macsec_newlink()") Date: Sun, 15 Apr 2018 00:31:21 +0200 Message-ID: <20180414223121.GA7475@bistromath.localdomain> References: <9a3a84ff-1fd1-c063-0c50-a297d29a692b@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Dan Carpenter , "David S. Miller" , Linux Kernel Mailing List , netdev@vger.kernel.org To: Laura Abbott Return-path: Content-Disposition: inline In-Reply-To: <9a3a84ff-1fd1-c063-0c50-a297d29a692b@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hello Laura, 2018-04-14, 10:56:55 -0700, Laura Abbott wrote: > Hi, > > Fedora got a bug report of a regression when trying to remove the > the macsec module (https://bugzilla.redhat.com/show_bug.cgi?id=1566410). > I did a bisect and found > > commit 5dcd8400884cc4a043a6d4617e042489e5d566a9 > Author: Dan Carpenter > Date: Wed Mar 21 11:09:01 2018 +0300 > > macsec: missing dev_put() on error in macsec_newlink() > We moved the dev_hold(real_dev); call earlier in the function but forgot > to update the error paths. > Fixes: 0759e552bce7 ("macsec: fix negative refcnt on parent link") > Signed-off-by: Dan Carpenter > Signed-off-by: David S. Miller > > The script I used for testing based on the reporter is attached. It > looks like modprobe is stuck in the D state. Any idea? I don't think that reference was actually leaked. It gets released in macsec_free_netdev() when the device is deleted. modprobe getting stuck is just a side-effect of the refcount going negative on the parent device, since removing the module needs to take the lock that is held by device deletion. I'll send a revert tomorrow. Thanks for the report, -- Sabrina