linux-kernel - [PATCH v2 net 2/7] tcp: use different parts of the port

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220428124001.7428-3-w@1wt.eu>
Date:   Thu, 28 Apr 2022 14:39:56 +0200
From:   Willy Tarreau <w@....eu>
To:     netdev@...r.kernel.org
Cc:     David Miller <davem@...emloft.net>,
        Jakub Kicinski <kuba@...nel.org>,
        Eric Dumazet <edumazet@...gle.com>,
        Moshe Kol <moshe.kol@...l.huji.ac.il>,
        Yossi Gilad <yossi.gilad@...l.huji.ac.il>,
        Amit Klein <aksecurity@...il.com>,
        "Jason A . Donenfeld" <Jason@...c4.com>,
        linux-kernel@...r.kernel.org, Willy Tarreau <w@....eu>
Subject: [PATCH v2 net 2/7] tcp: use different parts of the port_offset for index and offset

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@...c4.com>
Cc: Moshe Kol <moshe.kol@...l.huji.ac.il>
Cc: Yossi Gilad <yossi.gilad@...l.huji.ac.il>
Cc: Amit Klein <aksecurity@...il.com>
Reviewed-by: Eric Dumazet <edumazet@...gle.com>
Signed-off-by: Willy Tarreau <w@....eu>
---
 net/ipv4/inet_hashtables.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 9d24d9319f3d..29c701cd8312 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -777,7 +777,7 @@ 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.
-- 
2.17.5