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-rw-r--r--net/ipv4/icmp.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 8cebb476b3ab..b8607763d113 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -749,6 +749,11 @@ void __icmp_send(struct sk_buff *skb_in, int type, int code, __be32 info,
room = 576;
room -= sizeof(struct iphdr) + icmp_param.replyopts.opt.opt.optlen;
room -= sizeof(struct icmphdr);
+ /* Guard against tiny mtu. We need to include at least one
+ * IP network header for this message to make any sense.
+ */
+ if (room <= (int)sizeof(struct iphdr))
+ goto ende;
icmp_param.data_len = skb_in->len - icmp_param.offset;
if (icmp_param.data_len > room)