Re: [syzbot] [PATCH] can: ucan: Correct the size parameter

[syzbot <syzbot+d7d8c418e8317899e88c@syzkaller.appspotmail.com>]

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***

Subject: [PATCH] can: ucan: Correct the size parameter
Author: zoo868e@gmail.com

According to the comment, the size parameter is only required when
@dst is not an array, or when the copy needs to be smaller than
sizeof(@dst). Since the source is a `union ucan_ctl_payload`, the
correct size should be sizeof(union ucan_ctl_payload).

#syz test

Signed-off-by: Matt Jan <zoo868e@gmail.com>
---
 drivers/net/can/usb/ucan.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/can/usb/ucan.c b/drivers/net/can/usb/ucan.c
index 39a63b7313a4..1ccef00388ae 100644
--- a/drivers/net/can/usb/ucan.c
+++ b/drivers/net/can/usb/ucan.c
@@ -1533,7 +1533,7 @@ static int ucan_probe(struct usb_interface *intf,
 	if (ret > 0) {
 		/* copy string while ensuring zero termination */
 		strscpy(firmware_str, up->ctl_msg_buffer->raw,
-			sizeof(union ucan_ctl_payload) + 1);
+			sizeof(union ucan_ctl_payload));
 	} else {
 		strcpy(firmware_str, "unknown");
 	}
-- 
2.25.1