From mboxrd@z Thu Jan 1 00:00:00 1970 From: Julia Lawall Date: Mon, 12 May 2008 14:37:46 +0000 Subject: Re: [PATCH 1/6] arch/ia64/kernel: remove null pointer dereference Message-Id: MIME-Version: 1 Content-Type: multipart/mixed; boundary="-511516320-175496707-1210603066=:3694" List-Id: References: <1210603050.25310.9.camel@odie.local> In-Reply-To: <1210603050.25310.9.camel@odie.local> To: Simon Holm =?ISO-8859-1?Q?Th=F8gersen?= Cc: tony.luck@intel.com, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-janitors@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---511516320-175496707-1210603066=:3694 Content-Type: TEXT/PLAIN; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable On Mon, 12 May 2008, Simon Holm Th=F8gersen wrote: > man, 12 05 2008 kl. 15:37 +0200, skrev Julia Lawall: > > From: Julia Lawall > >=20 > > If data is NULL, it is not possible to access data->ret. > >=20 > > The problem was detected using the following semantic match > > (http://www.emn.fr/x-info/coccinelle/) > >=20 > > // > > @@ > > expression E, E1; > > identifier f; > > statement S1,S2,S3; > > @@ > >=20 > > * if (E =3D=3D NULL) > > { > > ... when !=3D if (E =3D=3D NULL) S1 else S2 > > when !=3D E =3D E1 > > * E->f > > ... when any > > return ...; > > } > > else S3 > > // > >=20 > > Signed-off-by: Julia Lawall > >=20 > > --- > >=20 > > diff -u -p a/arch/ia64/kernel/palinfo.c b/arch/ia64/kernel/palinfo.c > > --- a/arch/ia64/kernel/palinfo.c 2008-05-09 16:46:57.000000000 +0200 > > +++ b/arch/ia64/kernel/palinfo.c 2008-05-12 08:43:35.000000000 +0200 > > @@ -902,7 +902,6 @@ palinfo_smp_call(void *info) > > palinfo_smp_data_t *data =3D (palinfo_smp_data_t *)info; > > if (data =3D=3D NULL) { > > printk(KERN_ERR "palinfo: data pointer is NULL\n"); > > - data->ret =3D 0; /* no output */ > > return; > > } > > /* does this actual call */ > > -- >=20 > The whole if block should just be deleted, as info is never NULL. There > is only palinfo_handle_smp as (indirect) user of palinfo_smp_call (by > way of smp_call_function_single) and surely palinfo_smp_call never pass > NULL. OK. Will you fix it? julia ---511516320-175496707-1210603066=:3694--