From b987b66ac3a2bc2f7b03a0ba48a07dc553100c07 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
Git-commit: b987b66ac3a2bc2f7b03a0ba48a07dc553100c07
Patch-mainline: v5.4-rc5
References: bsc#1051510
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>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/usb/gadget/udc/lpc32xx_udc.c | 6 +++---
1 file 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;
--
2.16.4