[PATCH 5.10 124/221] can: isotp: isotp_setsockopt(): only allow to set low level TX flags for CAN-FD

[Greg Kroah-Hartman]

From: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>

[ Upstream commit e4912459bd5edd493b61bc7c3a5d9b2eb17f5a89 ]

CAN-FD frames have struct canfd_frame::flags, while classic CAN frames
don't.

This patch refuses to set TX flags (struct
can_isotp_ll_options::tx_flags) on non CAN-FD isotp sockets.

Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Link: https://lore.kernel.org/r/20210218215434.1708249-2-mkl@xxxxxxxxxxxxxx
Cc: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/can/isotp.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/can/isotp.c b/net/can/isotp.c
index 8bd565f2073e..a9b96a6e6317 100644
--- a/net/can/isotp.c
+++ b/net/can/isotp.c
@@ -1212,7 +1212,8 @@ static int isotp_setsockopt(struct socket *sock, int level, int optname,
 			if (ll.mtu != CAN_MTU && ll.mtu != CANFD_MTU)
 				return -EINVAL;
 
-			if (ll.mtu == CAN_MTU && ll.tx_dl > CAN_MAX_DLEN)
+			if (ll.mtu == CAN_MTU &&
+			    (ll.tx_dl > CAN_MAX_DLEN || ll.tx_flags != 0))
 				return -EINVAL;
 
 			memcpy(&so->ll, &ll, sizeof(ll));
-- 
2.30.1