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

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

[gregkh]

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 <stable@vger.kernel.org> know about it.


>From foo@baz Mon May 16 11:20:33 PDT 2016
From: Paolo Abeni <pabeni@redhat.com>
Date: Fri, 13 May 2016 18:33:41 +0200
Subject: net/route: enforce hoplimit max value

From: Paolo Abeni <pabeni@redhat.com>

[ 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.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/fib_semantics.c |    2 ++
 net/ipv6/route.c         |    2 ++
 2 files changed, 4 insertions(+)

--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -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;
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -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 pabeni@redhat.com 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