mqprio: Avoid panic if no options are provided

[ Upstream commit 7838f2ce36b6ab5c13ef20b1857e3bbd567f1759 ]

Userspace may not provide TCA_OPTIONS, in fact tc currently does
so not do so if no arguments are specified on the command line.
Return EINVAL instead of panicing.

Signed-off-by: Thomas Graf <tgraf@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index ea17cbed29eff7215c062efe04c32de6bf513596..59b26b8ff4b0bd8f89d87ce99f9a114b96240408 100644 (file)
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -106,7 +106,7 @@ static int mqprio_init(struct Qdisc *sch, struct nlattr *opt)
        if (!netif_is_multiqueue(dev))
                return -EOPNOTSUPP;
 
-       if (nla_len(opt) < sizeof(*qopt))
+       if (!opt || nla_len(opt) < sizeof(*qopt))
                return -EINVAL;
 
        qopt = nla_data(opt);