Commit ff621985 authored Jan 05, 2016 by Hannes Frederic Sowa Committed by David S. Miller Jan 05, 2016

bridge: Only call /sbin/bridge-stp for the initial network namespace

[I stole this patch from Eric Biederman. He wrote:]

> There is no defined mechanism to pass network namespace information
> into /sbin/bridge-stp therefore don't even try to invoke it except
> for bridge devices in the initial network namespace.
>
> It is possible for unprivileged users to cause /sbin/bridge-stp to be
> invoked for any network device name which if /sbin/bridge-stp does not
> guard against unreasonable arguments or being invoked twice on the
> same network device could cause problems.

[Hannes: changed patch using netns_eq]

Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent c845acb3

net/bridge/br_stp_if.c

+4 −1

Original line number	Original line	Diff line number	Diff line
	@@ -142,7 +142,10 @@ static void br_stp_start(struct net_bridge *br)
	char *envp[] = { NULL };		char *envp[] = { NULL };
	struct net_bridge_port *p;		struct net_bridge_port *p;

			if (net_eq(dev_net(br->dev), &init_net))
	r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);		r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
			else
			r = -ENOENT;

	spin_lock_bh(&br->lock);		spin_lock_bh(&br->lock);

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