diff options
Diffstat (limited to 'net/ipv6/seg6_iptunnel.c')
| -rw-r--r-- | net/ipv6/seg6_iptunnel.c | 29 |
1 files changed, 22 insertions, 7 deletions
diff --git a/net/ipv6/seg6_iptunnel.c b/net/ipv6/seg6_iptunnel.c index 4bf937bfc263..51583461ae29 100644 --- a/net/ipv6/seg6_iptunnel.c +++ b/net/ipv6/seg6_iptunnel.c @@ -472,23 +472,35 @@ static int seg6_input_core(struct net *net, struct sock *sk, { struct dst_entry *orig_dst = skb_dst(skb); struct dst_entry *dst = NULL; + struct lwtunnel_state *lwtst; struct seg6_lwt *slwt; int err; - slwt = seg6_lwt_lwtunnel(orig_dst->lwtstate); + /* We cannot dereference "orig_dst" once ip6_route_input() or + * skb_dst_drop() is called. However, in order to detect a dst loop, we + * need the address of its lwtstate. So, save the address of lwtstate + * now and use it later as a comparison. + */ + lwtst = orig_dst->lwtstate; + + slwt = seg6_lwt_lwtunnel(lwtst); local_bh_disable(); dst = dst_cache_get(&slwt->cache); local_bh_enable(); err = seg6_do_srh(skb, dst); - if (unlikely(err)) + if (unlikely(err)) { + dst_release(dst); goto drop; + } if (!dst) { ip6_route_input(skb); dst = skb_dst(skb); - if (!dst->error) { + + /* cache only if we don't create a dst reference loop */ + if (!dst->error && lwtst != dst->lwtstate) { local_bh_disable(); dst_cache_set_ip6(&slwt->cache, dst, &ipv6_hdr(skb)->saddr); @@ -571,13 +583,15 @@ static int seg6_output_core(struct net *net, struct sock *sk, dst = ip6_route_output(net, NULL, &fl6); if (dst->error) { err = dst->error; - dst_release(dst); goto drop; } - local_bh_disable(); - dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); - local_bh_enable(); + /* cache only if we don't create a dst reference loop */ + if (orig_dst->lwtstate != dst->lwtstate) { + local_bh_disable(); + dst_cache_set_ip6(&slwt->cache, dst, &fl6.saddr); + local_bh_enable(); + } err = skb_cow_head(skb, LL_RESERVED_SPACE(dst->dev)); if (unlikely(err)) @@ -593,6 +607,7 @@ static int seg6_output_core(struct net *net, struct sock *sk, return dst_output(net, sk, skb); drop: + dst_release(dst); kfree_skb(skb); return err; } |