1 files changed, 21 insertions, 29 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index b6ddf23d3833..dbc224023977 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -41,6 +41,7 @@
 #include <linux/nsproxy.h>
 #include <linux/slab.h>
 #include <linux/jhash.h>
+#include <linux/siphash.h>
 #include <net/net_namespace.h>
 #include <net/snmp.h>
 #include <net/ipv6.h>
@@ -1484,17 +1485,24 @@ static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
 static u32 rt6_exception_hash(const struct in6_addr *dst,
 			      const struct in6_addr *src)
 {
-	static u32 seed __read_mostly;
-	u32 val;
+	static siphash_key_t rt6_exception_key __read_mostly;
+	struct {
+		struct in6_addr dst;
+		struct in6_addr src;
+	} __aligned(SIPHASH_ALIGNMENT) combined = {
+		.dst = *dst,
+	};
+	u64 val;
 
-	net_get_random_once(&seed, sizeof(seed));
-	val = jhash2((const u32 *)dst, sizeof(*dst)/sizeof(u32), seed);
+	net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
 
 #ifdef CONFIG_IPV6_SUBTREES
 	if (src)
-		val = jhash2((const u32 *)src, sizeof(*src)/sizeof(u32), val);
+		combined.src = *src;
 #endif
-	return hash_32(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
+	val = siphash(&combined, sizeof(combined), &rt6_exception_key);
+
+	return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
 }
 
 /* Helper function to find the cached rt in the hash table
@@ -1649,6 +1657,7 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 	struct in6_addr *src_key = NULL;
 	struct rt6_exception *rt6_ex;
 	struct fib6_nh *nh = res->nh;
+	int max_depth;
 	int err = 0;
 
 	spin_lock_bh(&rt6_exception_lock);
@@ -1703,7 +1712,9 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 	bucket->depth++;
 	net->ipv6.rt6_stats->fib_rt_cache++;
 
-	if (bucket->depth > FIB6_MAX_DEPTH)
+	/* Randomize max depth to avoid some side channels attacks. */
+	max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH);
+	while (bucket->depth > max_depth)
 		rt6_exception_remove_oldest(bucket);
 
 out:
@@ -3201,25 +3212,7 @@ static unsigned int ip6_default_advmss(const struct dst_entry *dst)
 
 INDIRECT_CALLABLE_SCOPE unsigned int ip6_mtu(const struct dst_entry *dst)
 {
-	struct inet6_dev *idev;
-	unsigned int mtu;
-
-	mtu = dst_metric_raw(dst, RTAX_MTU);
-	if (mtu)
-		goto out;
-
-	mtu = IPV6_MIN_MTU;
-
-	rcu_read_lock();
-	idev = __in6_dev_get(dst->dev);
-	if (idev)
-		mtu = idev->cnf.mtu6;
-	rcu_read_unlock();
-
-out:
-	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
-
-	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
+	return ip6_dst_mtu_maybe_forward(dst, false);
 }
 EXPORT_INDIRECT_CALLABLE(ip6_mtu);
 
@@ -3644,8 +3637,7 @@ out:
 	if (err) {
 		lwtstate_put(fib6_nh->fib_nh_lws);
 		fib6_nh->fib_nh_lws = NULL;
-		if (dev)
-			dev_put(dev);
+		dev_put(dev);
 	}
 
 	return err;
@@ -6638,7 +6630,7 @@ int __init ip6_route_init(void)
 	ret = -ENOMEM;
 	ip6_dst_ops_template.kmem_cachep =
 		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
-				  SLAB_HWCACHE_ALIGN, NULL);
+				  SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
 	if (!ip6_dst_ops_template.kmem_cachep)
 		goto out;