From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D537815C82 for ; Mon, 5 Dec 2022 19:20:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 598FBC433C1; Mon, 5 Dec 2022 19:20:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1670268048; bh=Y+4xl1S/Avm7ArvBM3OMahKepe8+qINUtjbIuBjOSZU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JyfBASsAVFXD+Gnn9EVpJg/MRgJbRNwzcu6WEaVmIL44jfKskLmfz1U2p1Q23n73z mxTTcwbe2r6k7cUnDagc1QbzILftwmpmWoIRsUCS3nR9CSzeXRxfvV3/YR67r3pgos GCoApfh9CxK8c+5ffbewmrU/yGmoP+jY2i/+JwiM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kuniyuki Iwashima , Joanne Koong , Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 029/105] dccp/tcp: Reset saddr on failure after inet6?_hash_connect(). Date: Mon, 5 Dec 2022 20:09:01 +0100 Message-Id: <20221205190804.130005429@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221205190803.124472741@linuxfoundation.org> References: <20221205190803.124472741@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Kuniyuki Iwashima [ Upstream commit 77934dc6db0d2b111a8f2759e9ad2fb67f5cffa5 ] When connect() is called on a socket bound to the wildcard address, we change the socket's saddr to a local address. If the socket fails to connect() to the destination, we have to reset the saddr. However, when an error occurs after inet_hash6?_connect() in (dccp|tcp)_v[46]_conect(), we forget to reset saddr and leave the socket bound to the address. >>From the user's point of view, whether saddr is reset or not varies with errno. Let's fix this inconsistent behaviour. Note that after this patch, the repro [0] will trigger the WARN_ON() in inet_csk_get_port() again, but this patch is not buggy and rather fixes a bug papering over the bhash2's bug for which we need another fix. For the record, the repro causes -EADDRNOTAVAIL in inet_hash6_connect() by this sequence: s1 = socket() s1.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) s1.bind(('127.0.0.1', 10000)) s1.sendto(b'hello', MSG_FASTOPEN, (('127.0.0.1', 10000))) # or s1.connect(('127.0.0.1', 10000)) s2 = socket() s2.setsockopt(SOL_SOCKET, SO_REUSEADDR, 1) s2.bind(('0.0.0.0', 10000)) s2.connect(('127.0.0.1', 10000)) # -EADDRNOTAVAIL s2.listen(32) # WARN_ON(inet_csk(sk)->icsk_bind2_hash != tb2); [0]: https://syzkaller.appspot.com/bug?extid=015d756bbd1f8b5c8f09 Fixes: 3df80d9320bc ("[DCCP]: Introduce DCCPv6") Fixes: 7c657876b63c ("[DCCP]: Initial implementation") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Acked-by: Joanne Koong Reviewed-by: Eric Dumazet Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/dccp/ipv4.c | 2 ++ net/dccp/ipv6.c | 2 ++ net/ipv4/tcp_ipv4.c | 2 ++ net/ipv6/tcp_ipv6.c | 2 ++ 4 files changed, 8 insertions(+) diff --git a/net/dccp/ipv4.c b/net/dccp/ipv4.c index 7e93087d1366..c021d5dde8f7 100644 --- a/net/dccp/ipv4.c +++ b/net/dccp/ipv4.c @@ -134,6 +134,8 @@ int dccp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) * This unhashes the socket and releases the local port, if necessary. */ dccp_set_state(sk, DCCP_CLOSED); + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + inet_reset_saddr(sk); ip_rt_put(rt); sk->sk_route_caps = 0; inet->inet_dport = 0; diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c index ae4851fdbe9e..72803e1ea10a 100644 --- a/net/dccp/ipv6.c +++ b/net/dccp/ipv6.c @@ -957,6 +957,8 @@ static int dccp_v6_connect(struct sock *sk, struct sockaddr *uaddr, late_failure: dccp_set_state(sk, DCCP_CLOSED); + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + inet_reset_saddr(sk); __sk_dst_reset(sk); failure: inet->inet_dport = 0; diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 6549e07ce19c..bd374eac9a75 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -328,6 +328,8 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) * if necessary. */ tcp_set_state(sk, TCP_CLOSE); + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + inet_reset_saddr(sk); ip_rt_put(rt); sk->sk_route_caps = 0; inet->inet_dport = 0; diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index 7a5a7a4265cf..babf69b2403b 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -327,6 +327,8 @@ static int tcp_v6_connect(struct sock *sk, struct sockaddr *uaddr, late_failure: tcp_set_state(sk, TCP_CLOSE); + if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) + inet_reset_saddr(sk); failure: inet->inet_dport = 0; sk->sk_route_caps = 0; -- 2.35.1