From: Willy Tarreau <w@1wt.eu>
Date: Mon, 2 May 2022 10:46:09 +0200
Subject: tcp: use different parts of the port_offset for index and offset
Patch-mainline: v5.18-rc6
Git-commit: 9e9b70ae923baf2b5e8a0ea4fd0c8451801ac526
References: CVE-2022-1012 CVE-2022-32296 bsc#1199482 bsc#1200288
Amit Klein suggests that we use different parts of port_offset for the
table's index and the port offset so that there is no direct relation
between them.
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: Eric Dumazet <edumazet@google.com>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
net/ipv4/inet_hashtables.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -766,7 +766,7 @@ 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;
+ offset = READ_ONCE(table_perturb[index]) + (port_offset >> 32);
offset %= remaining;
/* In first pass we try ports of @low parity.