Commit 626abd59 authored May 13, 2016 by Paolo Abeni Committed by David S. Miller May 14, 2016

net/route: enforce hoplimit max value



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>

parent 31b0b385

net/ipv4/fib_semantics.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -975,6 +975,8 @@ fib_convert_metrics(struct fib_info fi, const struct fib_config cfg)
		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;

net/ipv6/route.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1750,6 +1750,8 @@ static int ip6_convert_metrics(struct mx6_config *mxc,
		} else {
		val = nla_get_u32(nla);
		}
		if (type == RTAX_HOPLIMIT && val > 255)
		val = 255;
		if (type == RTAX_FEATURES && (val & ~RTAX_FEATURE_MASK))
		goto err;

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