lkml.org 
[lkml]   [2021]   [Apr]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] usb: gadget: prevent a ternary sign expansion bug
The problem is that "req->actual" is a u32, "req->status" is an int, and
iocb->ki_complete() takes a long. We would expect that a negative error
code in "req->status" would translate to a negative long value.

But what actually happens is that because "req->actual" is a u32, the
error codes is type promoted to a high positive value and then remains
a positive value when it is cast to long. (No sign expansion).

We can fix this by casting "req->status" to long.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
drivers/usb/gadget/legacy/inode.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/usb/gadget/legacy/inode.c b/drivers/usb/gadget/legacy/inode.c
index 71e7d10dd76b..cd8e2737947b 100644
--- a/drivers/usb/gadget/legacy/inode.c
+++ b/drivers/usb/gadget/legacy/inode.c
@@ -498,7 +498,8 @@ static void ep_aio_complete(struct usb_ep *ep, struct usb_request *req)
iocb->private = NULL;
/* aio_complete() reports bytes-transferred _and_ faults */

- iocb->ki_complete(iocb, req->actual ? req->actual : req->status,
+ iocb->ki_complete(iocb,
+ req->actual ? req->actual : (long)req->status,
req->status);
} else {
/* ep_copy_to_user() won't report both; we hide some faults */
--
2.30.2
\
 
 \ /
  Last update: 2021-04-22 11:02    [W:0.039 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site