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Date:   Wed, 11 Sep 2019 11:41:11 +0300
From:   Dan Carpenter <dan.carpenter@oracle.com>
To:     Sandro Volery <sandro@volery.com>
Cc:     valdis.kletnieks@vt.edu, gregkh@linuxfoundation.org,
        devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Staging: exfat: Avoid use of strcpy
Message-ID: <20190911084111.GG15977@kadam>
References: <20190911055749.GA10786@volery>
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On Wed, Sep 11, 2019 at 07:57:49AM +0200, Sandro Volery wrote:
> Replaced strcpy with strscpy in exfat_core.c.
> 
> Signed-off-by: Sandro Volery <sandro@volery.com>
> ---
>  drivers/staging/exfat/exfat_core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/staging/exfat/exfat_core.c b/drivers/staging/exfat/exfat_core.c
> index da8c58149c35..c71b145e8a24 100644
> --- a/drivers/staging/exfat/exfat_core.c
> +++ b/drivers/staging/exfat/exfat_core.c
> @@ -2964,7 +2964,7 @@ s32 resolve_path(struct inode *inode, char *path, struct chain_t *p_dir,
>  	if (strlen(path) >= (MAX_NAME_LENGTH * MAX_CHARSET_SIZE))
>  		return FFS_INVALIDPATH;
>  
> -	strcpy(name_buf, path);
> +	strscpy(name_buf, path, sizeof(name_buf));

It checked strlen() earlier so we know that it can't overflow but, oh
wow, the "name_buf" is a shared buffer.  wow wow wow.  This seems very
racy.

regards,
dan carpenter