diff options
authorDaniel Borkmann <>2014-12-10 16:33:10 +0100
committerGreg Kroah-Hartman <>2014-12-16 09:39:06 -0800
commit4b1c83d8c3dd4e11da7e1f4fc8c5cd513b77a0fe (patch)
parent01da9f8b6b2ccc4f24aea3d4c46af1a3efbd0241 (diff)
netlink: use jhash as hashfn for rhashtable
[ Upstream commit 7f19fc5e0b617593dcda0d9956adc78b559ef1f5 ] For netlink, we shouldn't be using arch_fast_hash() as a hashing discipline, but rather jhash() instead. Since netlink sockets can be opened by any user, a local attacker would be able to easily create collisions with the DPDK-derived arch_fast_hash(), which trades off performance for security by using crc32 CPU instructions on x86_64. While it might have a legimite use case in other places, it should be avoided in netlink context, though. As rhashtable's API is very flexible, we could later on still decide on other hashing disciplines, if legitimate. Reference: Fixes: e341694e3eb5 ("netlink: Convert netlink_lookup() to use RCU protected hash table") Cc: Herbert Xu <> Signed-off-by: Daniel Borkmann <> Acked-by: Thomas Graf <> Acked-by: Hannes Frederic Sowa <> Signed-off-by: David S. Miller <> Signed-off-by: Greg Kroah-Hartman <>
1 files changed, 1 insertions, 1 deletions
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 0007b8180397..b6bf8e8caec7 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -3130,7 +3130,7 @@ static int __init netlink_proto_init(void)
.head_offset = offsetof(struct netlink_sock, node),
.key_offset = offsetof(struct netlink_sock, portid),
.key_len = sizeof(u32), /* portid */
- .hashfn = arch_fast_hash,
+ .hashfn = jhash,
.max_shift = 16, /* 64K */
.grow_decision = rht_grow_above_75,
.shrink_decision = rht_shrink_below_30,