355b985537
net_hash_mix() currently uses kernel address of a struct net,
and is used in many places that could be used to reveal this
address to a patient attacker, thus defeating KASLR, for
the typical case (initial net namespace, &init_net is
not dynamically allocated)
I believe the original implementation tried to avoid spending
too many cycles in this function, but security comes first.
Also provide entropy regardless of CONFIG_NET_NS.
Fixes: 0b4419162a ("netns: introduce the net_hash_mix "salt" for hashes")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
12 lines
212 B
C
12 lines
212 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __NET_NS_HASH_H__
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#define __NET_NS_HASH_H__
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#include <net/net_namespace.h>
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static inline u32 net_hash_mix(const struct net *net)
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{
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return net->hash_mix;
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}
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#endif
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