diff options
| author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2023-09-11 11:36:57 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-09-13 07:18:04 +0100 |
| commit | c48ef9c4aed3632566b57ba66cec6ec78624d4cb (patch) | |
| tree | 94904a626367a70ed2cbdd01c79bb2df6810bc9d /net/ipv4 | |
| parent | aa99e5f87bd54db55dd37cb130bd5eb55933027f (diff) | |
tcp: Fix bind() regression for v4-mapped-v6 non-wildcard address.
Since bhash2 was introduced, the example below does not work as expected.
These two bind() should conflict, but the 2nd bind() now succeeds.
from socket import *
s1 = socket(AF_INET6, SOCK_STREAM)
s1.bind(('::ffff:127.0.0.1', 0))
s2 = socket(AF_INET, SOCK_STREAM)
s2.bind(('127.0.0.1', s1.getsockname()[1]))
During the 2nd bind() in inet_csk_get_port(), inet_bind2_bucket_find()
fails to find the 1st socket's tb2, so inet_bind2_bucket_create() allocates
a new tb2 for the 2nd socket. Then, we call inet_csk_bind_conflict() that
checks conflicts in the new tb2 by inet_bhash2_conflict(). However, the
new tb2 does not include the 1st socket, thus the bind() finally succeeds.
In this case, inet_bind2_bucket_match() must check if AF_INET6 tb2 has
the conflicting v4-mapped-v6 address so that inet_bind2_bucket_find()
returns the 1st socket's tb2.
Note that if we bind two sockets to 127.0.0.1 and then ::FFFF:127.0.0.1,
the 2nd bind() fails properly for the same reason mentinoed in the previous
commit.
Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/inet_hashtables.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index a58b04052ca6..c32f5e28758b 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -820,8 +820,13 @@ static bool inet_bind2_bucket_match(const struct inet_bind2_bucket *tb, return false; #if IS_ENABLED(CONFIG_IPV6) - if (sk->sk_family != tb->family) + if (sk->sk_family != tb->family) { + if (sk->sk_family == AF_INET) + return ipv6_addr_v4mapped(&tb->v6_rcv_saddr) && + tb->v6_rcv_saddr.s6_addr32[3] == sk->sk_rcv_saddr; + return false; + } if (sk->sk_family == AF_INET6) return ipv6_addr_equal(&tb->v6_rcv_saddr, &sk->sk_v6_rcv_saddr); |