ipv4: use siphash instead of Jenkins in fnhe_hashfun()

ANBZ: torvalds#535 commit 6457378 ("ipv4: use siphash instead of Jenkins in fnhe_hashfun()") 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: d546c62 ("ipv4: harden fnhe_hashfun()") Signed-off-by: Eric Dumazet <[email protected]> Reported-by: Keyu Man <[email protected]> Cc: Willy Tarreau <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Xuan Zhuo <[email protected]> Acked-by: Dust Li <[email protected]>
gatieme · Feb 23, 2022 · e87fd0f · e87fd0f
1 parent 0b19032
commit e87fd0f
Showing 1 changed file with 6 additions and 6 deletions.
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
@@ -612,14 +612,14 @@ static struct fib_nh_exception *fnhe_oldest(struct fnhe_hash_bucket *hash)
  return oldest;
 }
 
-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)