From db2773d65b02aed319a93efdfb958087771d4e19 Mon Sep 17 00:00:00 2001
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Thu, 6 Apr 2023 13:08:45 +0200
Subject: [PATCH] can: isotp: recvmsg(): allow MSG_CMSG_COMPAT flag
Git-commit: db2773d65b02aed319a93efdfb958087771d4e19
Patch-mainline: v6.4-rc3
References: git-fixes

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")
Link: https://lore.kernel.org/20230505110308.81087-2-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 net/can/isotp.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1018,7 +1018,7 @@ static int isotp_recvmsg(struct socket *
 	int noblock = flags & MSG_DONTWAIT;
 	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)