From: Hannes Frederic Sowa <han...@stressinduktion.org>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
[ Upstream commit ff62198553e43cdffa9d539f6165d3e83f8a42bc ]
[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 <ebied...@xmission.com>
Signed-off-by: Eric W. Biederman <ebied...@xmission.com>
Signed-off-by: Hannes Frederic Sowa <han...@stressinduktion.org>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Jiri Slaby <jsl...@suse.cz>
---
net/bridge/br_stp_if.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 886f6d6dc48a..3995a66c3e4e 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -128,7 +128,10 @@ static void br_stp_start(struct net_bridge *br)
char *argv[] = { BR_STP_PROG, br->dev->name, "start", NULL };
char *envp[] = { NULL };
- r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+ if (net_eq(dev_net(br->dev), &init_net))
+ r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+ else
+ r = -ENOENT;
spin_lock_bh(&br->lock);
--
2.7.1
