Patch "netns: Fail conspicously if someone uses net_generic at an inappropriate time." has been added to the 3.2-stable tree

Patch "netns: Fail conspicously if someone uses net_generic at an inappropriate time." has been added to the 3.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    netns: Fail conspicously if someone uses net_generic at an inappropriate time.

to the 3.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netns-fail-conspicously-if-someone-uses-net_generic-at-an-inappropriate-time.patch
and it can be found in the queue-3.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From edfae7e59c985de33d2f09e4a260a0d26b376f7d Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Thu, 26 Jan 2012 14:02:55 +0000
Subject: netns: Fail conspicously if someone uses net_generic at an inappropriate time.


From: "Eric W. Biederman" <ebiederm@xmission.com>

[ Upstream commit 5ee4433efe99b9f39f6eff5052a177bbcfe72cea ]

By definition net_generic should never be called when it can return
NULL.  Fail conspicously with a BUG_ON to make it clear when people mess
up that a NULL return should never happen.

Recently there was a bug in the CAIF subsystem where it was registered
with register_pernet_device instead of register_pernet_subsys.  It was
erroneously concluded that net_generic could validly return NULL and
that net_assign_generic was buggy (when it was just inefficient).
Hopefully this BUG_ON will prevent people to coming to similar erroneous
conclusions in the futrue.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
 include/net/netns/generic.h |    1 +
 1 file changed, 1 insertion(+)

--- a/include/net/netns/generic.h
+++ b/include/net/netns/generic.h
@@ -41,6 +41,7 @@ static inline void *net_generic(const st
 	ptr = ng->ptr[id - 1];
 	rcu_read_unlock();
 
+	BUG_ON(!ptr);
 	return ptr;
 }
 #endif


Patches currently in stable-queue which might be from ebiederm@xmission.com are

queue-3.2/sysfs-complain-bitterly-about-attempts-to-remove-files-from-nonexistent-directories.patch
queue-3.2/usb-io_ti-make-edge_remove_sysfs_attrs-the-port_remove-method.patch
queue-3.2/net-caif-register-properly-as-a-pernet-subsystem.patch
queue-3.2/netns-fix-net_alloc_generic.patch
queue-3.2/netns-fail-conspicously-if-someone-uses-net_generic-at-an-inappropriate-time.patch