ipv4: use siphash instead of Jenkins in fnhe_hashfun()

commit 6457378fe796815c973f631a1904e147d6ee33b1 upstream.

A group of security researchers brought to our attention
the weakness of hash function used in fnhe_hashfun().

Lets use siphash instead of Jenkins Hash, to considerably
reduce security risks.

Also remove the inline keyword, this really is distracting.

Fixes: d546c62154 ("ipv4: harden fnhe_hashfun()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
[OP: adjusted context for 5.4 stable]
Signed-off-by: Ovidiu Panait <ovidiu.panait@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Eric Dumazet 2021-10-28 20:56:31 +03:00 committed by Greg Kroah-Hartman
parent 3f439c231a
commit 4ba6c163fe

View File

@ -631,14 +631,14 @@ static void fnhe_remove_oldest(struct fnhe_hash_bucket *hash)
kfree_rcu(oldest, rcu);
}
static inline u32 fnhe_hashfun(__be32 daddr)
static u32 fnhe_hashfun(__be32 daddr)
{
static u32 fnhe_hashrnd __read_mostly;
u32 hval;
static siphash_key_t fnhe_hash_key __read_mostly;
u64 hval;
net_get_random_once(&fnhe_hashrnd, sizeof(fnhe_hashrnd));
hval = jhash_1word((__force u32) daddr, fnhe_hashrnd);
return hash_32(hval, FNHE_HASH_SHIFT);
net_get_random_once(&fnhe_hash_key, sizeof(fnhe_hash_key));
hval = siphash_1u32((__force u32)daddr, &fnhe_hash_key);
return hash_64(hval, FNHE_HASH_SHIFT);
}
static void fill_route_from_fnhe(struct rtable *rt, struct fib_nh_exception *fnhe)