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.
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
net/bridge/br_stp_if.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c
index 5396ff08af32..742fa89528ab 100644
--- a/net/bridge/br_stp_if.c
+++ b/net/bridge/br_stp_if.c
@@ -142,7 +142,9 @@ static void br_stp_start(struct net_bridge *br)
char *envp[] = { NULL };
struct net_bridge_port *p;
- r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
+ r = -ENOENT;
+ if (dev_net(br->dev) == &init_net)
+ r = call_usermodehelper(BR_STP_PROG, argv, envp, UMH_WAIT_PROC);
spin_lock_bh(&br->lock);
--
2.2.1
