[PATCH 05/13] fs: check FMODE_WRITE in __kernel_write

[Matthew Wilcox]

On Mon, Jun 15, 2020 at 02:12:49PM +0200, Christoph Hellwig wrote:
> We still need to check if the fѕ is open write, even for the low-level
> helper.

Do we need the analogous check for FMODE_READ in the __kernel_read()
patch?

> @@ -505,6 +505,8 @@ ssize_t __kernel_write(struct file *file, const void *buf, size_t count, loff_t
>  	const char __user *p;
>  	ssize_t ret;
>  
> +	if (!(file->f_mode & FMODE_WRITE))
> +		return -EBADF;
>  	if (!(file->f_mode & FMODE_CAN_WRITE))
>  		return -EINVAL;
>  
> -- 
> 2.26.2
>