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authorEric Dumazet <edumazet@google.com>2021-08-26 01:17:29 +0200
committerDavid S. Miller <davem@davemloft.net>2021-08-26 11:20:34 +0200
commit6457378fe796815c973f631a1904e147d6ee33b1 (patch)
treea1011494e41faacba2c0d400f5c7554028d83489 /net/ipv4
parentipv6: use siphash in rt6_exception_hash() (diff)
downloadlinux-6457378fe796815c973f631a1904e147d6ee33b1.tar.xz
linux-6457378fe796815c973f631a1904e147d6ee33b1.zip
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: d546c621542d ("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>
Diffstat (limited to 'net/ipv4')
-rw-r--r--net/ipv4/route.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 99c06944501a..a6f20ee35335 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -600,14 +600,14 @@ 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)