1 files changed, 10 insertions, 6 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index d5d20cde8d92..6e3ddf806ec2 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1098,11 +1098,12 @@ static inline struct ipv6_rt_hdr *ip6_rthdr_dup(struct ipv6_rt_hdr *src,
         return src ? kmemdup(src, (src->hdrlen + 1) * 8, gfp) : NULL;
 }
 
-static void ip6_append_data_mtu(int *mtu,
+static void ip6_append_data_mtu(unsigned int *mtu,
                                 int *maxfraglen,
                                 unsigned int fragheaderlen,
                                 struct sk_buff *skb,
-                                struct rt6_info *rt)
+                                struct rt6_info *rt,
+                                bool pmtuprobe)
 {
         if (!(rt->dst.flags & DST_XFRM_TUNNEL)) {
                 if (skb == NULL) {
@@ -1114,7 +1115,9 @@ static void ip6_append_data_mtu(int *mtu,
                          * this fragment is not first, the headers
                          * space is regarded as data space.
                          */
-                        *mtu = dst_mtu(rt->dst.path);
+                        *mtu = min(*mtu, pmtuprobe ?
+                                   rt->dst.dev->mtu :
+                                   dst_mtu(rt->dst.path));
                 }
                 *maxfraglen = ((*mtu - fragheaderlen) & ~7)
                               + fragheaderlen - sizeof(struct frag_hdr);
@@ -1131,11 +1134,10 @@ int ip6_append_data(struct sock *sk, int getfrag(void *from, char *to,
         struct ipv6_pinfo *np = inet6_sk(sk);
         struct inet_cork *cork;
         struct sk_buff *skb, *skb_prev = NULL;
-        unsigned int maxfraglen, fragheaderlen;
+        unsigned int maxfraglen, fragheaderlen, mtu;
         int exthdrlen;
         int dst_exthdrlen;
         int hh_len;
-        int mtu;
         int copy;
         int err;
         int offset = 0;
@@ -1292,7 +1294,9 @@ alloc_new_skb:
                         /* update mtu and maxfraglen if necessary */
                         if (skb == NULL || skb_prev == NULL)
                                 ip6_append_data_mtu(&mtu, &maxfraglen,
-                                                    fragheaderlen, skb, rt);
+                                                    fragheaderlen, skb, rt,
+                                                    np->pmtudisc ==
+                                                    IPV6_PMTUDISC_PROBE);
 
                         skb_prev = skb;