[PATCH v3 1/2] can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flag - Marc Kleine-Budde

From: Marc Kleine-Budde <mkl@pengutronix.de>
To: linux-can@vger.kernel.org
Cc: kernel@pengutronix.de, Oliver Hartkopp <socketcan@hartkopp.net>,
	Oleksij Rempel <o.rempel@pengutronix.de>,
	Marc Kleine-Budde <mkl@pengutronix.de>
Subject: [PATCH v3 1/2] can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flag
Date: Fri,  5 May 2023 13:03:07 +0200	[thread overview]
Message-ID: <20230505110308.81087-2-mkl@pengutronix.de> (raw)
In-Reply-To: <20230505110308.81087-1-mkl@pengutronix.de>

From: Oliver Hartkopp <socketcan@hartkopp.net>

The control message provided by isotp support MSG_CMSG_COMPAT but
blocked recvmsg() syscalls that have set this flag, i.e. on 32bit user
space on 64 bit kernels.

Link: https://github.com/hartkopp/can-isotp/issues/59
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Fixes: 42bf50a1795a ("can: isotp: support MSG_TRUNC flag when reading from socket")
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
---
 net/can/isotp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/can/isotp.c b/net/can/isotp.c
index a750259cb79c..84f9aba02901 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1139,7 +1139,7 @@ static int isotp_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
 	struct isotp_sock *so = isotp_sk(sk);
 	int ret = 0;
 
-	if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK))
+	if (flags & ~(MSG_DONTWAIT | MSG_TRUNC | MSG_PEEK | MSG_CMSG_COMPAT))
 		return -EINVAL;
 
 	if (!so->bound)
-- 
2.39.2


