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author | Kuniyuki Iwashima <kuniyu@amazon.com> | 2024-03-26 23:42:45 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-10 17:38:06 +0300 |
commit | fd17771f676d093c6e6c8b1260e502cb0e3ca045 (patch) | |
tree | 976e2ae5f60d51756eb115892f4a4c77213837e5 | |
parent | d0f44075c6e2b0dd2c0716558d005eb1de75a23a (diff) | |
download | linux-fd17771f676d093c6e6c8b1260e502cb0e3ca045.tar.xz |
tcp: Fix bind() regression for v6-only wildcard and v4(-mapped-v6) non-wildcard addresses.
commit d91ef1e1b55f730bee8ce286b02b7bdccbc42973 upstream.
Jianguo Wu reported another bind() regression introduced by bhash2.
Calling bind() for the following 3 addresses on the same port, the
3rd one should fail but now succeeds.
1. 0.0.0.0 or ::ffff:0.0.0.0
2. [::] w/ IPV6_V6ONLY
3. IPv4 non-wildcard address or v4-mapped-v6 non-wildcard address
The first two bind() create tb2 like this:
bhash2 -> tb2(:: w/ IPV6_V6ONLY) -> tb2(0.0.0.0)
The 3rd bind() will match with the IPv6 only wildcard address bucket
in inet_bind2_bucket_match_addr_any(), however, no conflicting socket
exists in the bucket. So, inet_bhash2_conflict() will returns false,
and thus, inet_bhash2_addr_any_conflict() returns false consequently.
As a result, the 3rd bind() bypasses conflict check, which should be
done against the IPv4 wildcard address bucket.
So, in inet_bhash2_addr_any_conflict(), we must iterate over all buckets.
Note that we cannot add ipv6_only flag for inet_bind2_bucket as it
would confuse the following patetrn.
1. [::] w/ SO_REUSE{ADDR,PORT} and IPV6_V6ONLY
2. [::] w/ SO_REUSE{ADDR,PORT}
3. IPv4 non-wildcard address or v4-mapped-v6 non-wildcard address
The first bind() would create a bucket with ipv6_only flag true,
the second bind() would add the [::] socket into the same bucket,
and the third bind() could succeed based on the wrong assumption
that ipv6_only bucket would not conflict with v4(-mapped-v6) address.
Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Diagnosed-by: Jianguo Wu <wujianguo106@163.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20240326204251.51301-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | net/ipv4/inet_connection_sock.c | 19 |
1 files changed, 11 insertions, 8 deletions
diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index b624271dccf1..d1492c649aea 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -294,6 +294,7 @@ static bool inet_bhash2_addr_any_conflict(const struct sock *sk, int port, int l struct sock_reuseport *reuseport_cb; struct inet_bind_hashbucket *head2; struct inet_bind2_bucket *tb2; + bool conflict = false; bool reuseport_cb_ok; rcu_read_lock(); @@ -306,18 +307,20 @@ static bool inet_bhash2_addr_any_conflict(const struct sock *sk, int port, int l spin_lock(&head2->lock); - inet_bind_bucket_for_each(tb2, &head2->chain) - if (inet_bind2_bucket_match_addr_any(tb2, net, port, l3mdev, sk)) - break; + inet_bind_bucket_for_each(tb2, &head2->chain) { + if (!inet_bind2_bucket_match_addr_any(tb2, net, port, l3mdev, sk)) + continue; - if (tb2 && inet_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok, - reuseport_ok)) { - spin_unlock(&head2->lock); - return true; + if (!inet_bhash2_conflict(sk, tb2, uid, relax, reuseport_cb_ok, reuseport_ok)) + continue; + + conflict = true; + break; } spin_unlock(&head2->lock); - return false; + + return conflict; } /* |