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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2019-10-14 14:18:30 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-15 20:07:44 +0200 |
| commit | b987b66ac3a2bc2f7b03a0ba48a07dc553100c07 (patch) | |
| tree | dafe4ff18c32248c18d3ac9ebe60c8d82df8ae89 /drivers | |
| parent | f616c3bda47e314ddb797e969f27081f3c33e3b3 (diff) | |
| download | linux-b987b66ac3a2bc2f7b03a0ba48a07dc553100c07.tar.bz2 | |
usb: udc: lpc32xx: fix bad bit shift operation
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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/usb/gadget/udc/lpc32xx_udc.c | 6 |
1 files changed, 3 insertions, 3 deletions
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; |