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authorPaolo Abeni <pabeni@redhat.com>2023-02-07 14:04:14 +0100
committerDavid S. Miller <davem@davemloft.net>2023-02-08 09:39:34 +0000
commit21e43569685de4ad773fb060c11a15f3fd5e7ac4 (patch)
tree9b0b464844a8dd4b1d42f9806ba76ee2eb718e35 /net/mptcp
parentd4e85922e3e7ef2071f91f65e61629b60f3a9cf4 (diff)
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mptcp: fix locking for setsockopt corner-case
We need to call the __mptcp_nmpc_socket(), and later subflow socket access under the msk socket lock, or e.g. a racing connect() could change the socket status under the hood, with unexpected results. Fixes: 54635bd04701 ("mptcp: add TCP_FASTOPEN_CONNECT socket option") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/mptcp')
-rw-r--r--net/mptcp/sockopt.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/net/mptcp/sockopt.c b/net/mptcp/sockopt.c
index d4b1e6ec1b36..7f2c3727ab23 100644
--- a/net/mptcp/sockopt.c
+++ b/net/mptcp/sockopt.c
@@ -760,14 +760,21 @@ static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname,
static int mptcp_setsockopt_first_sf_only(struct mptcp_sock *msk, int level, int optname,
sockptr_t optval, unsigned int optlen)
{
+ struct sock *sk = (struct sock *)msk;
struct socket *sock;
+ int ret = -EINVAL;
/* Limit to first subflow, before the connection establishment */
+ lock_sock(sk);
sock = __mptcp_nmpc_socket(msk);
if (!sock)
- return -EINVAL;
+ goto unlock;
- return tcp_setsockopt(sock->sk, level, optname, optval, optlen);
+ ret = tcp_setsockopt(sock->sk, level, optname, optval, optlen);
+
+unlock:
+ release_sock(sk);
+ return ret;
}
static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname,