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Commit ab5b00cf authored by Willy Tarreau's avatar Willy Tarreau Committed by Greg Kroah-Hartman
Browse files

secure_seq: use the 64 bits of the siphash for port offset calculation 



commit b2d057560b8107c633b39aabe517ff9d93f285e3 upstream.

SipHash replaced MD5 in secure_ipv{4,6}_port_ephemeral() via commit
7cd23e53 ("secure_seq: use SipHash in place of MD5"), but the output
remained truncated to 32-bit only. In order to exploit more bits from the
hash, let's make the functions return the full 64-bit of siphash_3u32().
We also make sure the port offset calculation in __inet_hash_connect()
remains done on 32-bit to avoid the need for div_u64_rem() and an extra
cost on 32-bit systems.

Cc: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Moshe Kol <moshe.kol@mail.huji.ac.il>
Cc: Yossi Gilad <yossi.gilad@mail.huji.ac.il>
Cc: Amit Klein <aksecurity@gmail.com>
Reviewed-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
[SG: Adjusted context]
Signed-off-by: default avatarStefan Ghinea <stefan.ghinea@windriver.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 80cca53a

include/net/inet_hashtables.h

+1 −1
Original line number Diff line number Diff line
@@ -420,7 +420,7 @@ static inline void sk_rcv_saddr_set(struct sock *sk, __be32 addr) 
}



int __inet_hash_connect(struct inet_timewait_death_row *death_row,

			struct sock *sk, u32 port_offset,

			struct sock *sk, u64 port_offset,

			int (*check_established)(struct inet_timewait_death_row *,

						 struct sock *, __u16,

						 struct inet_timewait_sock **));

include/net/secure_seq.h

+2 −2
Original line number Diff line number Diff line
@@ -4,8 +4,8 @@ 


#include <linux/types.h>



u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport);

u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,

u64 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport);

u64 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,

			       __be16 dport);

u32 secure_tcp_seq(__be32 saddr, __be32 daddr,

		   __be16 sport, __be16 dport);

net/core/secure_seq.c

+2 −2
Original line number Diff line number Diff line
@@ -97,7 +97,7 @@ u32 secure_tcpv6_seq(const __be32 *saddr, const __be32 *daddr, 
}

EXPORT_SYMBOL(secure_tcpv6_seq);



u32 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,

u64 secure_ipv6_port_ephemeral(const __be32 *saddr, const __be32 *daddr,

			       __be16 dport)

{

	const struct {
@@ -147,7 +147,7 @@ u32 secure_tcp_seq(__be32 saddr, __be32 daddr, 
}

EXPORT_SYMBOL_GPL(secure_tcp_seq);



u32 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)

u64 secure_ipv4_port_ephemeral(__be32 saddr, __be32 daddr, __be16 dport)

{

	net_secret_init();

	return siphash_4u32((__force u32)saddr, (__force u32)daddr,

net/ipv4/inet_hashtables.c

+6 −4
Original line number Diff line number Diff line
@@ -464,7 +464,7 @@ static int __inet_check_established(struct inet_timewait_death_row *death_row, 
	return -EADDRNOTAVAIL;

}



static u32 inet_sk_port_offset(const struct sock *sk)

static u64 inet_sk_port_offset(const struct sock *sk)

{

	const struct inet_sock *inet = inet_sk(sk);
@@ -683,7 +683,7 @@ EXPORT_SYMBOL_GPL(inet_unhash); 
static u32 table_perturb[1 << INET_TABLE_PERTURB_SHIFT];



int __inet_hash_connect(struct inet_timewait_death_row *death_row,

		struct sock *sk, u32 port_offset,

		struct sock *sk, u64 port_offset,

		int (*check_established)(struct inet_timewait_death_row *,

			struct sock *, __u16, struct inet_timewait_sock **))

{
@@ -726,7 +726,9 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, 
	net_get_random_once(table_perturb, sizeof(table_perturb));

	index = hash_32(port_offset, INET_TABLE_PERTURB_SHIFT);



	offset = (READ_ONCE(table_perturb[index]) + port_offset) % remaining;

	offset = READ_ONCE(table_perturb[index]) + port_offset;

	offset %= remaining;



	/* In first pass we try ports of @low parity.

	 * inet_csk_get_port() does the opposite choice.

	 */
@@ -803,7 +805,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, 
int inet_hash_connect(struct inet_timewait_death_row *death_row,

		      struct sock *sk)

{

	u32 port_offset = 0;

	u64 port_offset = 0;



	if (!inet_sk(sk)->inet_num)

		port_offset = inet_sk_port_offset(sk);

net/ipv6/inet6_hashtables.c

+2 −2
Original line number Diff line number Diff line
@@ -262,7 +262,7 @@ static int __inet6_check_established(struct inet_timewait_death_row *death_row, 
	return -EADDRNOTAVAIL;

}



static u32 inet6_sk_port_offset(const struct sock *sk)

static u64 inet6_sk_port_offset(const struct sock *sk)

{

	const struct inet_sock *inet = inet_sk(sk);
@@ -274,7 +274,7 @@ static u32 inet6_sk_port_offset(const struct sock *sk) 
int inet6_hash_connect(struct inet_timewait_death_row *death_row,

		       struct sock *sk)

{

	u32 port_offset = 0;

	u64 port_offset = 0;



	if (!inet_sk(sk)->inet_num)

		port_offset = inet6_sk_port_offset(sk);