| From 6b2bc716e044f0067cbf52754ff10cb5ab46ff67 Mon Sep 17 00:00:00 2001 |
| From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> |
| Date: Mon, 14 Oct 2019 14:18:30 -0500 |
| Subject: [PATCH] usb: udc: lpc32xx: fix bad bit shift operation |
| |
| commit b987b66ac3a2bc2f7b03a0ba48a07dc553100c07 upstream. |
| |
| It seems that the right variable to use in this case is *i*, instead of |
| *n*, otherwise there is an undefined behavior when right shifiting by more |
| than 31 bits when multiplying n by 8; notice that *n* can take values |
| equal or greater than 4 (4, 8, 16, ...). |
| |
| Also, notice that under the current conditions (bl = 3), we are skiping |
| the handling of bytes 3, 7, 31... So, fix this by updating this logic |
| and limit *bl* up to 4 instead of up to 3. |
| |
| This fix is based on function udc_stuff_fifo(). |
| |
| Addresses-Coverity-ID: 1454834 ("Bad bit shift operation") |
| Fixes: 24a28e428351 ("USB: gadget driver for LPC32xx") |
| Cc: stable@vger.kernel.org |
| Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> |
| Link: https://lore.kernel.org/r/20191014191830.GA10721@embeddedor |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> |
| |
| diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c |
| index 5f1b14f3e5a0..36b7dd7bebf6 100644 |
| --- a/drivers/usb/gadget/udc/lpc32xx_udc.c |
| +++ b/drivers/usb/gadget/udc/lpc32xx_udc.c |
| @@ -1180,11 +1180,11 @@ static void udc_pop_fifo(struct lpc32xx_udc *udc, u8 *data, u32 bytes) |
| tmp = readl(USBD_RXDATA(udc->udp_baseaddr)); |
| |
| bl = bytes - n; |
| - if (bl > 3) |
| - bl = 3; |
| + if (bl > 4) |
| + bl = 4; |
| |
| for (i = 0; i < bl; i++) |
| - data[n + i] = (u8) ((tmp >> (n * 8)) & 0xFF); |
| + data[n + i] = (u8) ((tmp >> (i * 8)) & 0xFF); |
| } |
| break; |
| |
| -- |
| 2.7.4 |
| |
