linux-kernel - Re: [PATCH] ssb:: use put_device() if device

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20180307183858.63172de9@wiggum>
Date:   Wed, 7 Mar 2018 18:38:58 +0100
From:   Michael Büsch <m@...s.ch>
To:     arvindY <arvind.yadav.cs@...il.com>
Cc:     linux-kernel@...r.kernel.org, linux-wireless@...r.kernel.org
Subject: Re: [PATCH] ssb:: use put_device() if device_register fail

On Wed, 7 Mar 2018 22:46:14 +0530
arvindY <arvind.yadav.cs@...il.com> wrote:
> >> diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
> >> index 65420a9..c4449e0 100644
> >> --- a/drivers/ssb/main.c
> >> +++ b/drivers/ssb/main.c
> >> @@ -521,6 +521,7 @@ static int ssb_devices_register(struct ssb_bus *bus)
> >>   			ssb_err("Could not register %s\n", dev_name(dev));
> >>   			/* Set dev to NULL to not unregister
> >>   			 * dev on error unwinding. */
> >> +			put_device(dev);
> >>   			sdev->dev = NULL;
> >>   			kfree(devwrap);
> >>   			goto error;  
> >
> > I don't think this is correct.
> > The dev structure is allocated as part of devwrap, which is freed here.
> >
> > Why do you think we need put_device here?
> >  
> Yes this patch is not correct, We must not use kfree() after you called 
> device_register() (even
> if it was not successful!) -- see the comment for device_register().
> I will delete kfree() and send updated patch.


Is device_put() going to call ssb_release_dev() to free the structure?

Can you please elaborate on why device_put() must be used? The comment
is not really of any use here.

-- 
Michael

Content of type "application/pgp-signature" skipped