diff options
| -rw-r--r-- | net/netfilter/xt_TCPMSS.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/net/netfilter/xt_TCPMSS.c b/net/netfilter/xt_TCPMSS.c index e4ee4bc81ff..a1bc77fcd68 100644 --- a/net/netfilter/xt_TCPMSS.c +++ b/net/netfilter/xt_TCPMSS.c @@ -88,8 +88,11 @@ tcpmss_mangle_packet(struct sk_buff *skb, oldmss = (opt[i+2] << 8) | opt[i+3]; - if (info->mss == XT_TCPMSS_CLAMP_PMTU && - oldmss <= newmss) + /* Never increase MSS, even when setting it, as + * doing so results in problems for hosts that rely + * on MSS being set correctly. + */ + if (oldmss <= newmss) return 0; opt[i+2] = (newmss & 0xff00) >> 8; |