diff -drupN a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
--- a/net/ipv6/ndisc.c	2018-08-06 17:23:04.000000000 +0300
+++ b/net/ipv6/ndisc.c	2022-06-12 05:28:14.000000000 +0300
@@ -1395,6 +1395,8 @@ skip_linkparms:
 			if (ri->prefix_len == 0 &&
 			    !in6_dev->cnf.accept_ra_defrtr)
 				continue;
+			if (ri->prefix_len < in6_dev->cnf.accept_ra_rt_info_min_plen)
+				continue;
 			if (ri->prefix_len > in6_dev->cnf.accept_ra_rt_info_max_plen)
 				continue;
 			rt6_route_rcv(skb->dev, (u8 *)p, (p->nd_opt_len) << 3,