From: ebiederm@xmission•com (Eric W. Biederman)
To: David Miller <davem@davemloft•net>
Cc: eric.dumazet@gmail•com, xemul@parallels•com,
sjur.brandeland@stericsson•com, levinsasha928@gmail•com,
netdev@vger•kernel.org, linux-kernel@vger•kernel.org,
davej@redhat•com, sjurbren@gmail•com
Subject: [PATCH 1/2] netns: Fail conspicously if someone uses net_generic at an inappropriate time.
Date: Thu, 26 Jan 2012 16:02:55 -0800 [thread overview]
Message-ID: <m1ehumc8r4.fsf_-_@fess.ebiederm.org> (raw)
In-Reply-To: <20120126.180754.679593869814492219.davem@davemloft.net> (David Miller's message of "Thu, 26 Jan 2012 18:07:54 -0500 (EST)")
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>
---
include/net/netns/generic.h | 1 +
1 files changed, 1 insertions(+), 0 deletions(-)
diff --git a/include/net/netns/generic.h b/include/net/netns/generic.h
index 3419bf5..d55f434 100644
--- a/include/net/netns/generic.h
+++ b/include/net/netns/generic.h
@@ -41,6 +41,7 @@ static inline void *net_generic(const struct net *net, int id)
ptr = ng->ptr[id - 1];
rcu_read_unlock();
+ BUG_ON(!ptr);
return ptr;
}
#endif
--
1.7.2.5
next prev parent reply other threads:[~2012-01-27 0:02 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-24 7:30 [PATCH] net: caif: Don't act on notification for non-caif devices Sasha Levin
2012-01-24 10:52 ` Sjur Brændeland
2012-01-24 14:49 ` Sasha Levin
2012-01-24 15:06 ` Sjur Brændeland
2012-01-24 15:23 ` Sasha Levin
[not found] ` <1327444045-1033-1-git-send-email-sjur.brandeland@stericsson.com>
2012-01-25 16:13 ` [PATCH net] caif: Fix crash due to uninitialized net name-space Sasha Levin
2012-01-25 20:33 ` Sjur Brændeland
2012-01-26 6:14 ` Eric Dumazet
2012-01-26 10:41 ` [PATCH] netns: fix net_alloc_generic() Eric Dumazet
2012-01-26 10:44 ` Pavel Emelyanov
2012-01-26 10:51 ` Eric Dumazet
2012-01-26 22:57 ` Eric W. Biederman
2012-01-26 23:07 ` David Miller
2012-01-26 23:57 ` Eric W. Biederman
2012-01-27 0:02 ` Eric W. Biederman [this message]
2012-01-27 0:04 ` [PATCH 2/2] net caif: Register properly as a pernet subsystem Eric W. Biederman
2012-01-27 13:24 ` Sasha Levin
2012-01-27 14:48 ` Sjur BRENDELAND
2012-01-28 2:07 ` David Miller
2012-01-28 2:07 ` [PATCH 1/2] netns: Fail conspicously if someone uses net_generic at an inappropriate time David Miller
2012-01-27 6:09 ` [PATCH] netns: fix net_alloc_generic() Eric Dumazet
2012-01-27 6:54 ` Eric W. Biederman
2012-01-27 7:07 ` Eric Dumazet
2012-01-26 14:40 ` Sasha Levin
2012-01-26 18:37 ` David Miller
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