From: Eric Dumazet <edumazet@xxxxxxxxxx> [ Upstream commit 2761121af87de45951989a0adada917837d8fa82 ] Do not assume the attribute has the right size. Fixes: aea5f654e6b7 ("net/sched: add skbprio scheduler") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/sched/sch_skbprio.c | 3 +++ 1 file changed, 3 insertions(+) --- a/net/sched/sch_skbprio.c +++ b/net/sched/sch_skbprio.c @@ -169,6 +169,9 @@ static int skbprio_change(struct Qdisc * { struct tc_skbprio_qopt *ctl = nla_data(opt); + if (opt->nla_len != nla_attr_size(sizeof(*ctl))) + return -EINVAL; + sch->limit = ctl->limit; return 0; }