macintosh/adb: fix oob read in do_adb_query() function

In do_adb_query() function of drivers/macintosh/adb.c, req->data is copied
form userland. The parameter "req->data[2]" is missing check, the array
size of adb_handler[] is 16, so adb_handler[req->data[2]].original_address and
adb_handler[req->data[2]].handler_id will lead to oob read.

Cc: stable <[e-mail]>
Signed-off-by: Ning Qiang <[e-mail]>
Reviewed-by: Kees Cook <[e-mail]>
Reviewed-by: Greg Kroah-Hartman <[e-mail]>
Acked-by: Benjamin Herrenschmidt <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

drivers/macintosh/adb.c

···
 
 	switch(req->data[1]) {
 	case ADB_QUERY_GETDEVINFO:
-		if (req->nbytes < 3)
+		if (req->nbytes < 3 || req->data[2] >= 16)
 			break;
 		mutex_lock(&adb_handler_mutex);
 		req->reply[0] = adb_handler[req->data[2]].original_address;