lkml.org 
[lkml]   [2020]   [Nov]   [2]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH AUTOSEL 5.8 26/29] usb: cdns3: gadget: suspicious implicit sign extension
Date
From: Peter Chen <peter.chen@nxp.com>

[ Upstream commit 5fca3f062879f8e5214c56f3e3e2be6727900f5d ]

The code:
trb->length = cpu_to_le32(TRB_BURST_LEN(priv_ep->trb_burst_size)
| TRB_LEN(length));

TRB_BURST_LEN(priv_ep->trb_burst_size) may be overflow for int 32 if
priv_ep->trb_burst_size is equal or larger than 0x80;

Below is the Coverity warning:
sign_extension: Suspicious implicit sign extension: priv_ep->trb_burst_size
with type u8 (8 bits, unsigned) is promoted in priv_ep->trb_burst_size << 24
to type int (32 bits, signed), then sign-extended to type unsigned long
(64 bits, unsigned). If priv_ep->trb_burst_size << 24 is greater than 0x7FFFFFFF,
the upper bits of the result will all be 1.

To fix it, it needs to add an explicit cast to unsigned int type for ((p) << 24).

Reviewed-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/cdns3/gadget.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/cdns3/gadget.h b/drivers/usb/cdns3/gadget.h
index 52765b098b9e1..28c4f6aca6891 100644
--- a/drivers/usb/cdns3/gadget.h
+++ b/drivers/usb/cdns3/gadget.h
@@ -1067,7 +1067,7 @@ struct cdns3_trb {
#define TRB_TDL_SS_SIZE_GET(p) (((p) & GENMASK(23, 17)) >> 17)

/* transfer_len bitmasks - bits 31:24 */
-#define TRB_BURST_LEN(p) (((p) << 24) & GENMASK(31, 24))
+#define TRB_BURST_LEN(p) ((unsigned int)((p) << 24) & GENMASK(31, 24))
#define TRB_BURST_LEN_GET(p) (((p) & GENMASK(31, 24)) >> 24)

/* Data buffer pointer bitmasks*/
--
2.27.0
\
 
 \ /
  Last update: 2020-11-03 02:25    [W:0.094 / U:12.976 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site