5.4-stable review patch. If anyone has any objections, please let me know.
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From: Xin Long lucien.xin@gmail.com
[ Upstream commit 4d5c70e6155d5eae198bade4afeab3c1b15073b6 ]
If hashing fails in sctp_listen_start(), the socket remains in the LISTENING state, even though it was not added to the hash table. This can lead to a scenario where a socket appears to be listening without actually being accessible.
This patch ensures that if the hashing operation fails, the sk_state is set back to CLOSED before returning an error.
Note that there is no need to undo the autobind operation if hashing fails, as the bind port can still be used for next listen() call on the same socket.
Fixes: 76c6d988aeb3 ("sctp: add sock_reuseport for the sock in __sctp_hash_endpoint") Reported-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Signed-off-by: Xin Long lucien.xin@gmail.com Acked-by: Marcelo Ricardo Leitner marcelo.leitner@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/sctp/socket.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index efc9981481c5f..4aee4fc05ba7c 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -8370,6 +8370,7 @@ static int sctp_listen_start(struct sock *sk, int backlog) struct sctp_endpoint *ep = sp->ep; struct crypto_shash *tfm = NULL; char alg[32]; + int err;
/* Allocate HMAC for generating cookie. */ if (!sp->hmac && sp->sctp_hmac_alg) { @@ -8397,18 +8398,25 @@ static int sctp_listen_start(struct sock *sk, int backlog) inet_sk_set_state(sk, SCTP_SS_LISTENING); if (!ep->base.bind_addr.port) { if (sctp_autobind(sk)) { - inet_sk_set_state(sk, SCTP_SS_CLOSED); - return -EAGAIN; + err = -EAGAIN; + goto err; } } else { if (sctp_get_port(sk, inet_sk(sk)->inet_num)) { - inet_sk_set_state(sk, SCTP_SS_CLOSED); - return -EADDRINUSE; + err = -EADDRINUSE; + goto err; } }
WRITE_ONCE(sk->sk_max_ack_backlog, backlog); - return sctp_hash_endpoint(ep); + err = sctp_hash_endpoint(ep); + if (err) + goto err; + + return 0; +err: + inet_sk_set_state(sk, SCTP_SS_CLOSED); + return err; }
/*