Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE into /proc tree

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To: Denis V. Lunev <den@...>

Cc: <akpm@...>, <linux-kernel@...>, Alexey Dobriyan <adobriyan@...>, Eric W. Biederman <ebiederm@...>, David S. Miller <davem@...>

Subject: Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE into /proc tree

Date: Friday, July 11, 2008 - 11:12 pm

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:
quoted text> 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.
quoted text> -
>        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

quoted text> +                            &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
>
> --
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Messages in current thread:

[PATCH 0/12] Further PDE->data assignments cleanups, Denis V. Lunev, (Tue Apr 29, 7:12 am)

[PATCH 8/12] powerpc: assign PDE->data before gluing PDE ..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

[PATCH 7/12] cciss: assign PDE->data before gluing PDE in..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

RE: [PATCH 7/12] cciss: assign PDE->data before gluing PD..., Miller, Mike (OS Dev), (Tue Apr 29, 11:26 am)

[PATCH 9/12] ipv4: assign PDE->data before gluing PDE int..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE..., Stoyan Gaydarov, (Fri Jul 11, 11:12 pm)

Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE..., Denis V. Lunev, (Sat Jul 12, 10:55 am)

Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE..., Eric W. Biederman, (Fri Jul 11, 11:42 pm)

Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE..., David Miller, (Fri May 2, 7:10 am)

[PATCH 3/12] net: assign PDE->data before gluing PDE into..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 3/12] net: assign PDE->data before gluing PDE ..., David Miller, (Fri May 2, 5:46 am)

[PATCH 5/12] atm: assign PDE->data before gluing PDE into..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 5/12] atm: assign PDE->data before gluing PDE ..., David Miller, (Fri May 2, 7:08 am)

[PATCH 4/12] ipv6: assign PDE->data before gluing PDE int..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 4/12] ipv6: assign PDE->data before gluing PDE..., David Miller, (Fri May 2, 5:47 am)

[PATCH 11/12] netfilter: assign PDE->data before gluing P..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 11/12] netfilter: assign PDE->data before glui..., David Miller, (Fri May 2, 7:12 am)

Re: [PATCH 11/12] netfilter: assign PDE->data before glui..., Patrick McHardy, (Tue Apr 29, 8:01 am)

[PATCH 10/12] netfilter: assign PDE->fops before gluing P..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 10/12] netfilter: assign PDE->fops before glui..., David Miller, (Fri May 2, 7:11 am)

[PATCH 6/12] vlan: assign PDE->data before gluing PDE int..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 6/12] vlan: assign PDE->data before gluing PDE..., David Miller, (Fri May 2, 7:09 am)

[PATCH 2/12] netfilter: assign PDE->data before gluing PD..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 2/12] netfilter: assign PDE->data before gluin..., David Miller, (Fri May 2, 5:45 am)

[PATCH 12/12] netns: assign PDE->data before gluing entry..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 12/12] netns: assign PDE->data before gluing e..., David Miller, (Fri May 2, 7:12 am)

[PATCH 1/12] sunrpc: assign PDE->data before gluing PDE i..., Denis V. Lunev, (Tue Apr 29, 7:13 am)

Re: [PATCH 1/12] sunrpc: assign PDE->data before gluing P..., David Miller, (Fri May 2, 5:44 am)


linux-kernel:
Rafael J. Wysocki	[Bug #10493] mips BCM47XX compile error
Ingo Molnar	[patch 02/13] syslets: add syslet.h include file, user API/ABI definitions
Greg KH	[GIT PATCH] driver core patches against 2.6.24
Andrea Arcangeli	[PATCH 00 of 11] mmu notifier #v16
git:

linux-netdev:
David Miller	Re: [PATCH] pkt_sched: Destroy gen estimators under rtnl_lock().
Gerrit Renker	[PATCH 27/37] dccp: Integration of dynamic feature activation - part 2 (server side)
Linus Torvalds	Re: [GIT]: Networking
Mark Lord	Re: [BUG] New Kernel Bugs
openbsd-misc:

Re: [PATCH 9/12] ipv4: assign PDE->data before gluing PDE into /proc tree

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