Hello Dan,
On Tue, 6 Oct 2015 21:51:55 +0300, Dan Carpenter <dan.carpenter@xxxxxxxxxx>
wrote:
> The patch 999b874f4aa3: "Input: joydev - validate axis/button maps
> before clobbering current ones" from Aug 25, 2009, leads to the
> following static checker warning:
>
> drivers/input/joydev.c:466 joydev_handle_JSIOCSAXMAP()
> error: 'abspam' dereferencing possible ERR_PTR()
>
> drivers/input/joydev.c
> 437 static int joydev_handle_JSIOCSAXMAP(struct joydev *joydev,
> 438 void __user *argp, size_t len)
> 439 {
> 440 __u8 *abspam;
> 441 int i;
> 442 int retval = 0;
> 443
> 444 len = min(len, sizeof(joydev->abspam));
> 445
> 446 /* Validate the map. */
> 447 abspam = memdup_user(argp, len);
> 448 if (IS_ERR(abspam)) {
> 449 retval = PTR_ERR(abspam);
> 450 goto out;
>
> out labels are error prone. It's safer to return directly.
>
> https://plus.google.com/106378716002406849458/posts/dnanfhQ4mHQ
>
> joydev_handle_JSIOCSBTNMAP() has the same issue.
Perhaps I'm missing something here, but that's not the code I wrote, nor is
it the code that's currently in the kernel. What I have in my copy of the
kernel tree is
/* Validate the map. */
abspam = kmalloc(len, GFP_KERNEL);
if (!abspam)
return -ENOMEM;
which does as you recommend. If you look up the commit you're referring to
you'll see that's also the code as I wrote it back in 2009; I'm not sure
where your IS_ERR() and PTR_ERR() stuff is coming from.
Regards,
Stephen
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