From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julia Lawall Subject: Re: [PATCH] net: dsa: loop: Check for memory allocation failure Date: Tue, 9 May 2017 07:46:34 +0800 (SGT) Message-ID: References: <20170506052945.2639-1-christophe.jaillet@wanadoo.fr> <063D6719AE5E284EB5DD2968C1650D6DCFFE715E@AcuExch.aculab.com> <1494265443.31950.62.camel@perches.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: David Laight , 'Christophe JAILLET' , "andrew@lunn.ch" , "vivien.didelot@savoirfairelinux.com" , "f.fainelli@gmail.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "kernel-janitors@vger.kernel.org" To: Joe Perches Return-path: In-Reply-To: <1494265443.31950.62.camel@perches.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 8 May 2017, Joe Perches wrote: > On Mon, 2017-05-08 at 20:32 +0800, Julia Lawall wrote: > > > > On Mon, 8 May 2017, David Laight wrote: > > > > > From: Christophe JAILLET > > > > Sent: 06 May 2017 06:30 > > > > If 'devm_kzalloc' fails, a NULL pointer will be dereferenced. > > > > Return -ENOMEM instead, as done for some other memory allocation just a > > > > few lines above. > > > > > > ... > > > > --- a/drivers/net/dsa/dsa_loop.c > > > > +++ b/drivers/net/dsa/dsa_loop.c > > > > @@ -256,6 +256,9 @@ static int dsa_loop_drv_probe(struct mdio_device *mdiodev) > > > > return -ENOMEM; > > > > > > > > ps = devm_kzalloc(&mdiodev->dev, sizeof(*ps), GFP_KERNEL); > > > > + if (!ps) > > > > + return -ENOMEM; > > > > + > > > > ps->netdev = dev_get_by_name(&init_net, pdata->netdev); > > > > if (!ps->netdev) > > > > return -EPROBE_DEFER; > > > > > > On the face if it this code leaks like a sieve. > > > > I don't think so. The allocations (dsa_switch_alloc and devm_kzalloc) use > > devm functions. > > It's at least wasteful. > > Each time -EPROBE_DEFER occurs, another set of calls to > dsa_switch_alloc and dev_kzalloc also occurs. > > Perhaps it'd be better to do: > > if (ps->netdev) { > devm_kfree(&devmdev->dev, ps); > devm_kfree(&mdiodev->dev, ds); > return -EPROBE_DEFER; > } Is EPROBE_DEFER handled differently than other kinds of errors? julia > > -- > To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >