From 4c619aa0ba171c092a0ae5d969364deb82dbe371 Mon Sep 17 00:00:00 2001
From: Andrew Morton <akpm@linux-foundation.org>
Date: Wed, 28 Mar 2012 14:42:52 -0700
Subject: [PATCH] fs/proc/namespaces.c: prevent crash when ns_entries[] is
empty
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.
Reported-by: Richard Weinberger <richard@nod.at>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/proc/namespaces.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/fs/proc/namespaces.c b/fs/proc/namespaces.c
index 3551f1f839eb..0d9e23a39e49 100644
--- a/fs/proc/namespaces.c
+++ b/fs/proc/namespaces.c
@@ -156,15 +156,15 @@ static struct dentry *proc_ns_dir_lookup(struct inode *dir,
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);
--
2.34.1