diff options
| author | Eric Dumazet <edumazet@google.com> | 2024-10-08 12:01:01 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-10-09 19:33:46 -0700 |
| commit | 4a0ec2aa0704c8271fde33a0f7bb92d09c066c17 (patch) | |
| tree | 9b651c6011530441df853a934244d746da9d568d /net/ipv6 | |
| parent | 2518b119639162251b6cc7195aec394930c1d867 (diff) | |
ipv6: switch inet6_addr_hash() to less predictable hash
In commit 3f27fb23219e ("ipv6: addrconf: add per netns perturbation
in inet6_addr_hash()"), I added net_hash_mix() in inet6_addr_hash()
to get better hash dispersion, at a time all netns were sharing the
hash table.
Since then, commit 21a216a8fc63 ("ipv6/addrconf: allocate a per
netns hash table") made the hash table per netns.
We could remove the net_hash_mix() from inet6_addr_hash(), but
there is still an issue with ipv6_addr_hash().
It is highly predictable and a malicious user can easily create
thousands of IPv6 addresses all stored in the same hash bucket.
Switch to __ipv6_addr_jhash(). We could use a dedicated
secret, or reuse net_hash_mix() as I did in this patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241008120101.734521-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/addrconf.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index 94dceac52884..f31528d4f694 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -1016,7 +1016,7 @@ ipv6_link_dev_addr(struct inet6_dev *idev, struct inet6_ifaddr *ifp) static u32 inet6_addr_hash(const struct net *net, const struct in6_addr *addr) { - u32 val = ipv6_addr_hash(addr) ^ net_hash_mix(net); + u32 val = __ipv6_addr_jhash(addr, net_hash_mix(net)); return hash_32(val, IN6_ADDR_HSIZE_SHIFT); } |