In rsvp_change(), the value of f->res.classid is checked to be no more than 255. Otherwise, the execution will goto errout. This is enforced by a if-statement check. However, in the following execution, f->res.classid is assigned with a new value returned from gen_tunnel(), and the new value is only checked against 0. Given that gen_tunnel() may return a value larger than 255 based on data, the new value of f->res.classid should be re-checked.
This patch adds a re-check to ensure the new value of f->res.classid is not great than 255; otherwise, an error code will be returned. Signed-off-by: Wenwen Wang <wang6...@umn.edu> --- net/sched/cls_rsvp.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/sched/cls_rsvp.h b/net/sched/cls_rsvp.h index 4f12976..7ced8fc 100644 --- a/net/sched/cls_rsvp.h +++ b/net/sched/cls_rsvp.h @@ -590,6 +590,9 @@ static int rsvp_change(struct net *net, struct sk_buff *in_skb, if (f->res.classid == 0 && (f->res.classid = gen_tunnel(data)) == 0) goto errout; + + if (f->res.classid > 255) + goto errout; } for (sp = &data->ht[h1]; -- 2.7.4