From 83f52aab42802b78c3d4a08b38cde60ff781fed2 Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 13 May 2016 18:33:41 +0200 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- net/ipv4/fib_semantics.c | 2 ++ net/ipv6/route.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index d97268e8ff103b..2b68418c719800 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -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; diff --git a/net/ipv6/route.c b/net/ipv6/route.c index d916d6ab9ad29a..6f32944e0223fc 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -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;