From: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
commit 3eb3d283e8579a22b81dd2ac3987b77465b2a22f upstream.
The read access to struct canxl_frame::len inside of a j1939 created
skbuff revealed a missing initialization of reserved and later filled
elements in struct can_frame.
This patch initializes the 8 byte CAN header with zero.
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-can/20221104052235.GA6474@xxxxxxxxxxxxxx
Reported-by: syzbot+d168ec0caca4697e03b1@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Oliver Hartkopp <socketcan@xxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20221104075000.105414-1-socketcan@xxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Marc Kleine-Budde <mkl@xxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/can/j1939/main.c | 3 +++
1 file changed, 3 insertions(+)
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -332,6 +332,9 @@ int j1939_send_one(struct j1939_priv *pr
/* re-claim the CAN_HDR from the SKB */
cf = skb_push(skb, J1939_CAN_HDR);
+ /* initialize header structure */
+ memset(cf, 0, J1939_CAN_HDR);
+
/* make it a full can frame again */
skb_put(skb, J1939_CAN_FTR + (8 - dlc));
