mirrors
/
linux-stable
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
1
0
Fork 0
Code Issues Releases Wiki Activity

tcp: Fix bind() regression for v6-only wildcard and v4-mapped-v6 non-wildcard addresses. 

Commit 5e07e67241 ("tcp: Use bhash2 for v4-mapped-v6 non-wildcard
address.") introduced bind() regression for v4-mapped-v6 address.

When we bind() the following two addresses on the same port, the 2nd
bind() should succeed but fails now.

  1. [::] w/ IPV6_ONLY
  2. ::ffff:127.0.0.1

After the chagne, v4-mapped-v6 uses bhash2 instead of bhash to
detect conflict faster, but I forgot to add a necessary change.

During the 2nd bind(), inet_bind2_bucket_match_addr_any() returns
the tb2 bucket of [::], and inet_bhash2_conflict() finally calls
inet_bind_conflict(), which returns true, meaning conflict.

  inet_bhash2_addr_any_conflict
  |- inet_bind2_bucket_match_addr_any  <-- return [::] bucket
  `- inet_bhash2_conflict
     `- __inet_bhash2_conflict <-- checks IPV6_ONLY for AF_INET
        |                          but not for v4-mapped-v6 address
        `- inet_bind_conflict  <-- does not check address

inet_bind_conflict() does not check socket addresses because
__inet_bhash2_conflict() is expected to do so.

However, it checks IPV6_V6ONLY attribute only against AF_INET
socket, and not for v4-mapped-v6 address.

As a result, v4-mapped-v6 address conflicts with v6-only wildcard
address.

To avoid that, let's add the missing test to use bhash2 for
v4-mapped-v6 address.

Fixes: 5e07e67241 ("tcp: Use bhash2 for v4-mapped-v6 non-wildcard address.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240326204251.51301-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Kuniyuki Iwashima 2024-03-26 13:42:44 -07:00 committed by Jakub Kicinski
parent 17af420545
commit ea11144950
1 changed files with 9 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

11
net/ipv4/inet_connection_sock.c
View File

@ -203,8 +203,15 @@ static bool __inet_bhash2_conflict(const struct sock *sk, struct sock *sk2,
kuid_t sk_uid, bool relax,
bool reuseport_cb_ok, bool reuseport_ok)
{
if (sk->sk_family == AF_INET && ipv6_only_sock(sk2))
return false;
if (ipv6_only_sock(sk2)) {
if (sk->sk_family == AF_INET)
return false;
#if IS_ENABLED(CONFIG_IPV6)
if (ipv6_addr_v4mapped(&sk->sk_v6_rcv_saddr))
return false;
#endif
}
return inet_bind_conflict(sk, sk2, sk_uid, relax,
reuseport_cb_ok, reuseport_ok);