From: Andrew Morton <akpm@linux-foundation.org>
To: Richard Weinberger <richard@nod.at>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
daniel.lezcano@free.fr,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: namespaces: Out-of-bounds array access
Date: Wed, 1 Feb 2012 15:21:12 -0800 [thread overview]
Message-ID: <20120201152112.d1ddda03.akpm@linux-foundation.org> (raw)
In-Reply-To: <4F063DE7.2080405@nod.at>
On Fri, 06 Jan 2012 01:18:47 +0100
Richard Weinberger <richard@nod.at> wrote:
> Hi!
>
> While searching a completely different bug I've found this problem:
> If CONFIG_NET_NS, CONFIG_UTS_NS and CONFIG_IPC_NS are disabled, ns_entries[]
> becomes empty and things like ns_entries[ARRAY_SIZE(ns_entries) - 1] will explode.
>
Presumably this will fix it:
--- a/fs/proc/namespaces.c~a
+++ a/fs/proc/namespaces.c
@@ -156,15 +156,15 @@ static struct dentry *proc_ns_dir_lookup
if (!ptrace_may_access(task, PTRACE_MODE_READ))
goto out;
- last = &ns_entries[ARRAY_SIZE(ns_entries) - 1];
- for (entry = ns_entries; entry <= last; entry++) {
+ last = &ns_entries[ARRAY_SIZE(ns_entries)];
+ for (entry = ns_entries; entry < last; entry++) {
if (strlen((*entry)->name) != len)
continue;
if (!memcmp(dentry->d_name.name, (*entry)->name, len))
break;
}
error = ERR_PTR(-ENOENT);
- if (entry > last)
+ if (entry == last)
goto out;
error = proc_ns_instantiate(dir, dentry, task, *entry);
_
But I wonder why we compile this file at all when ns_entries[] is
empty?
prev parent reply other threads:[~2012-02-01 23:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-06 0:18 namespaces: Out-of-bounds array access Richard Weinberger
2012-02-01 23:21 ` Andrew Morton [this message]
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