From 3eb3d283e8579a22b81dd2ac3987b77465b2a22f Mon Sep 17 00:00:00 2001
From: Oliver Hartkopp <socketcan@hartkopp.net>
Date: Fri, 4 Nov 2022 08:50:00 +0100
Subject: [PATCH] can: j1939: j1939_send_one(): fix missing CAN header initialization
Git-commit: 3eb3d283e8579a22b81dd2ac3987b77465b2a22f
Patch-mainline: v6.1-rc5
References: git-fixes
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@pengutronix.de>
Link: https://lore.kernel.org/linux-can/20221104052235.GA6474@pengutronix.de
Reported-by: syzbot+d168ec0caca4697e03b1@syzkaller.appspotmail.com
Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net>
Link: https://lore.kernel.org/all/20221104075000.105414-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
net/can/j1939/main.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c
index 144c86b0e3ff..821d4ff303b3 100644
--- a/net/can/j1939/main.c
+++ b/net/can/j1939/main.c
@@ -336,6 +336,9 @@ int j1939_send_one(struct j1939_priv *priv, struct sk_buff *skb)
/* 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));
--
2.35.3