X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=drivers%2Fusb%2Fstorage%2Ftransport.c;h=540add24a12ffa428bda0e7a0db07650ecd29eab;hb=919ba4ee1badf6247f8064bdec2c80e389b57c40;hp=b1d815eb6d0bb34d8edeff31581eafd1ad983a0c;hpb=41e950c033b7df997d4b38653efe6554be9b96a7;p=karo-tx-linux.git

diff --git a/drivers/usb/storage/transport.c b/drivers/usb/storage/transport.c
index b1d815eb6d0b..540add24a12f 100644
--- a/drivers/usb/storage/transport.c
+++ b/drivers/usb/storage/transport.c
@@ -1035,9 +1035,20 @@ int usb_stor_Bulk_max_lun(struct us_data *us)
 	usb_stor_dbg(us, "GetMaxLUN command result is %d, data is %d\n",
 		     result, us->iobuf[0]);
 
-	/* if we have a successful request, return the result */
-	if (result > 0)
-		return us->iobuf[0];
+	/*
+	 * If we have a successful request, return the result if valid. The
+	 * CBW LUN field is 4 bits wide, so the value reported by the device
+	 * should fit into that.
+	 */
+	if (result > 0) {
+		if (us->iobuf[0] < 16) {
+			return us->iobuf[0];
+		} else {
+			dev_info(&us->pusb_intf->dev,
+				 "Max LUN %d is not valid, using 0 instead",
+				 us->iobuf[0]);
+		}
+	}
 
 	/*
 	 * Some devices don't like GetMaxLUN.  They may STALL the control