From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Wed, 28 Feb 2018 12:56:29 +0100 From: Cornelia Huck Subject: Re: [PATCH] net: iucv: Free memory obtained by kzalloc Message-ID: <20180228125629.3062ac1d.cohuck@redhat.com> In-Reply-To: References: <6fbfc0b8aa75852c4eed4d05e4c165a493304ced.1519811528.git.arvind.yadav.cs@gmail.com> <20180228113042.6a2f5177.cohuck@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-Archive: List-Post: To: Arvind Yadav Cc: jwi@linux.vnet.ibm.com, ubraun@linux.vnet.ibm.com, davem@davemloft.net, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org List-ID: On Wed, 28 Feb 2018 17:14:55 +0530 Arvind Yadav wrote: > On Wednesday 28 February 2018 04:00 PM, Cornelia Huck wrote: > > On Wed, 28 Feb 2018 15:24:16 +0530 > > Arvind Yadav wrote: > > > >> Free memory, if afiucv_iucv_init is not successful and > >> removing a IUCV driver. > >> > >> Signed-off-by: Arvind Yadav > >> --- > >> net/iucv/af_iucv.c | 5 ++++- > >> 1 file changed, 4 insertions(+), 1 deletion(-) > >> > >> diff --git a/net/iucv/af_iucv.c b/net/iucv/af_iucv.c > >> index 1e8cc7b..eb0995a 100644 > >> --- a/net/iucv/af_iucv.c > >> +++ b/net/iucv/af_iucv.c > >> @@ -2433,9 +2433,11 @@ static int afiucv_iucv_init(void) > >> af_iucv_dev->driver = &af_iucv_driver; > >> err = device_register(af_iucv_dev); > >> if (err) > >> - goto out_driver; > >> + goto out_iucv_dev; > >> return 0; > >> > >> +out_iucv_dev: > >> + kfree(af_iucv_dev); > >> out_driver: > >> driver_unregister(&af_iucv_driver); > >> out_iucv: > >> @@ -2496,6 +2498,7 @@ static void __exit afiucv_exit(void) > >> { > >> if (pr_iucv) { > >> device_unregister(af_iucv_dev); > >> + kfree(af_iucv_dev); > >> driver_unregister(&af_iucv_driver); > >> pr_iucv->iucv_unregister(&af_iucv_handler, 0); > >> symbol_put(iucv_if); > > No, you must not use kfree() after you called device_register() (even > > if it was not successful!) -- see the comment for device_register(). > Yes, Your are right. First we need to call put_device() then kfree(). > I will send updated patch. No, that's not correct, either. device_register() will give up any reference it obtained, and the caller did not obtain any additional reference, so a put_device() would be wrong. A kfree() on a refcounted structure is wrong as well.