Re: [patch] sysfs: checking for NULL instead of ERR_PTR

[ebiederm@xmission.com (Eric W. Biederman)]

Dan Carpenter <error27@gmail.com> writes:

> d_path() returns an ERR_PTR and it doesn't return NULL.
>
> CC:stable@kernel.org
> Signed-off-by: Dan Carpenter <error27@gmail.com>

This is definitely a needed bug fix.

Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com>

If we ever get ERR_PTR(-ENAMETOOLONG) and this case actually matters 
something is very wrong with sysfs, but that is another story.

Eric


> diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
> index 1b27b56..da3fefe 100644
> --- a/fs/sysfs/file.c
> +++ b/fs/sysfs/file.c
> @@ -340,7 +340,7 @@ static int sysfs_open_file(struct inode *inode, struct file *file)
>  	char *p;
>  
>  	p = d_path(&file->f_path, last_sysfs_file, sizeof(last_sysfs_file));
> -	if (p)
> +	if (!IS_ERR(p))
>  		memmove(last_sysfs_file, p, strlen(p) + 1);
>  
>  	/* need attr_sd for attr and ops, its parent for kobj */