Messages in this thread | | | Date | Fri, 11 Jul 2008 22:12:30 -0500 | From | "Stoyan Gaydarov" <> | Subject | Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE into /proc tree |
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First off, sorry to bring such an old email back but I can seem to get a bad feeling when looking back over it.
On Tue, Apr 29, 2008 at 6:13 AM, Denis V. Lunev <den@openvz.org> wrote: > The check for PDE->data != NULL becomes useless after the replacement > of proc_net_fops_create with proc_create_data. > > Signed-off-by: Denis V. Lunev <den@openvz.org> > Cc: Alexey Dobriyan <adobriyan@openvz.org> > Cc: Eric W. Biederman <ebiederm@xmission.com> > Cc: David S. Miller <davem@davemloft.net> > --- > net/ipv4/tcp_ipv4.c | 10 +++------- > net/ipv4/udp.c | 7 +++---- > 2 files changed, 6 insertions(+), 11 deletions(-) > > diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c > index 7766151..4d97b28 100644 > --- a/net/ipv4/tcp_ipv4.c > +++ b/net/ipv4/tcp_ipv4.c > @@ -2214,9 +2214,6 @@ static int tcp_seq_open(struct inode *inode, struct file *file) > struct tcp_iter_state *s; > int err; > > - if (unlikely(afinfo == NULL)) > - return -EINVAL; I think that this check needs to stay in some form, reason below. > - > err = seq_open_net(inode, file, &afinfo->seq_ops, > sizeof(struct tcp_iter_state)); > if (err < 0) > @@ -2241,10 +2238,9 @@ int tcp_proc_register(struct net *net, struct tcp_seq_afinfo *afinfo) > afinfo->seq_ops.next = tcp_seq_next; > afinfo->seq_ops.stop = tcp_seq_stop; > > - p = proc_net_fops_create(net, afinfo->name, S_IRUGO, &afinfo->seq_fops); > - if (p) > - p->data = afinfo; > - else > + p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net,
When you try to pass in afinfo->name (and also the seq_fops) you are assuming that afinfo is not null meaning in the unlikely(as shown above) even that it is null you get a very bad null pointer problem. If I am just way off do let me know because this just seams to me like a bad idea. This is also still present in 2.6.26-rc9.
-Stoyan G
> + &afinfo->seq_fops, afinfo); > + if (!p) > rc = -ENOMEM; > return rc; > } > diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c > index b053ac7..c19c491 100644 > --- a/net/ipv4/udp.c > +++ b/net/ipv4/udp.c > @@ -1605,10 +1605,9 @@ int udp_proc_register(struct net *net, struct udp_seq_afinfo *afinfo) > afinfo->seq_ops.next = udp_seq_next; > afinfo->seq_ops.stop = udp_seq_stop; > > - p = proc_net_fops_create(net, afinfo->name, S_IRUGO, &afinfo->seq_fops); > - if (p) > - p->data = afinfo; > - else > + p = proc_create_data(afinfo->name, S_IRUGO, net->proc_net, > + &afinfo->seq_fops, afinfo); > + if (!p) > rc = -ENOMEM; > return rc; > } > -- > 1.5.3.rc5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ >
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