Patch "net/route: enforce hoplimit max value" has been added to the 4.5-stable tree

This is a note to let you know that I've just added the patch titled

net/route: enforce hoplimit max value

to the 4.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
net-route-enforce-hoplimit-max-value.patch
and it can be found in the queue-4.5 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Paolo Abeni <[email protected]>
Date: Fri, 13 May 2016 18:33:41 +0200
Subject: net/route: enforce hoplimit max value

From: Paolo Abeni <[email protected]>

[ Upstream commit 626abd59e51d4d8c6367e03aae252a8aa759ac78 ]

Currently, when creating or updating a route, no check is performed in both ipv4 and ipv6 code to the hoplimit value.

The caller can i.e. set hoplimit to 256, and when such route will
be used, packets will be sent with hoplimit/ttl equal to 0.

This commit adds checks for the RTAX_HOPLIMIT value, in both ipv4 ipv6 route code, substituting any value greater than 255 with 255.

This is consistent with what is currently done for ADVMSS and MTU in the ipv4 code.

---
 net/ipv4/fib_semantics.c |    2 ++
 net/ipv6/route.c         |    2 ++
 2 files changed, 4 insertions(+)

@@ -975,6 +975,8 @@ fib_convert_metrics(struct fib_info *fi,
 			val = 65535 - 40;
 		if (type == RTAX_MTU && val > 65535 - 15)
 			val = 65535 - 15;
+		if (type == RTAX_HOPLIMIT && val > 255)
+			val = 255;
 		if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK))
 			return -EINVAL;
 		fi->fib_metrics[type - 1] = val;

@@ -1737,6 +1737,8 @@ static int ip6_convert_metrics(struct mx
 		} else {
 			val = nla_get_u32(nla);
 		}
+		if (type == RTAX_HOPLIMIT && val > 255)
+			val = 255;
 		if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK))
 			goto err;
 

Patches currently in stable-queue which might be from [email protected] are

queue-4.5/ipv4-fib-don-t-warn-when-primary-address-is-missing-if-in_dev-is-dead.patch queue-4.5/net-route-enforce-hoplimit-max-value.patch