From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH 1/2] tun: Use memdup_user() rather than duplicating its implementation Date: Mon, 22 Aug 2016 04:43:53 +0300 Message-ID: <20160822044347-mutt-send-email-mst@kernel.org> References: <566ABCD9.1060404@users.sourceforge.net> <9cf06275-924d-6c22-d8a8-f733a03cca23@users.sourceforge.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jason Wang , Mike Rapoport , Paolo Abeni , Soheil Hassas Yeganeh , LKML , kernel-janitors@vger.kernel.org, Julia Lawall To: SF Markus Elfring Return-path: Content-Disposition: inline In-Reply-To: Sender: kernel-janitors-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Sat, Aug 20, 2016 at 09:34:56AM +0200, SF Markus Elfring wrote: > From: Markus Elfring > Date: Sat, 20 Aug 2016 08:54:15 +0200 > > Reuse existing functionality from memdup_user() instead of keeping > duplicate source code. > > This issue was detected by using the Coccinelle software. > > Signed-off-by: Markus Elfring Acked-by: Michael S. Tsirkin > --- > drivers/net/tun.c | 11 +++-------- > 1 file changed, 3 insertions(+), 8 deletions(-) > > diff --git a/drivers/net/tun.c b/drivers/net/tun.c > index 9c8b5bc..a1aeccb 100644 > --- a/drivers/net/tun.c > +++ b/drivers/net/tun.c > @@ -731,14 +731,9 @@ static int update_filter(struct tap_filter *filter, void __user *arg) > } > > alen = ETH_ALEN * uf.count; > - addr = kmalloc(alen, GFP_KERNEL); > - if (!addr) > - return -ENOMEM; > - > - if (copy_from_user(addr, arg + sizeof(uf), alen)) { > - err = -EFAULT; > - goto done; > - } > + addr = memdup_user(arg + sizeof(uf), alen); > + if (IS_ERR(addr)) > + return PTR_ERR(addr); > > /* The filter is updated without holding any locks. Which is > * perfectly safe. We disable it first and in the worst > -- > 2.9.3