From: Hannes Frederic Sowa Date: Tue, 5 Jan 2016 09:46:00 +0000 (+0100) Subject: bridge: Only call /sbin/bridge-stp for the initial network namespace X-Git-Tag: v3.2.80~28 X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=9def77212c9b8a2e35f28879363cbbbf34923b3d bridge: Only call /sbin/bridge-stp for the initial network namespace [ 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 Signed-off-by: Eric W. Biederman Signed-off-by: Hannes Frederic Sowa Signed-off-by: David S. Miller [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings --- diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index 0f7dc609f27d..afafe662d452 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -129,7 +129,10 @@ 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; if (r == 0) { br->stp_enabled = BR_USER_STP; br_debug(br, "userspace STP started\n");