| Message ID | 20191014191830.GA10721@embeddedor (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | b987b66ac3a2bc2f7b03a0ba48a07dc553100c07 |
| Headers | show |
| Series | usb: udc: lpc32xx: fix bad bit shift operation | expand |
diff --git a/drivers/usb/gadget/udc/lpc32xx_udc.c b/drivers/usb/gadget/udc/lpc32xx_udc.c index 2b1f3cc7819b..bf6c81e2f8cc 100644 --- a/drivers/usb/gadget/udc/lpc32xx_udc.c +++ b/drivers/usb/gadget/udc/lpc32xx_udc.c @@ -1177,11 +1177,11 @@ 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;
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> --- drivers/usb/gadget/udc/lpc32xx_udc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)