staging: rtl8723bs: add missing range check on id

The value of the u8 id needs to be upper bounds checked to ensure
the cam_cache array on the adapter dvobj is not indexed outside
of the allowed range of 0..TOTAL_CAM_ENTRY-1. This can currently
occur if id is >= TOTAL_CAM_ENTRY when calling write_cam_from_cache.
Fix this by adding an upper range check.

Detected by CoverityScan, CID#1428464 ("Use of untrusted scalar value")

Fixes: 554c0a3abf21 ("staging: Add rtl8723bs sdio wifi driver")
Signed-off-by: Colin Ian King <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/rtl8723bs/os_dep/rtw_proc.c

···
 
 		if (num < 2)
 			return count;
+		if (id >= TOTAL_CAM_ENTRY)
+			return -EINVAL;
 
 		if (strcmp("c", cmd) == 0) {
 			_clear_cam_entry(adapter, id);