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

From: Matthew Wilcox
Date: Mon Jun 15 2020 - 08:34:58 EST


On Mon, Jun 15, 2020 at 02:12:49PM +0200, Christoph Hellwig wrote:
> We still need to check if the fÑ 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
>