[PATCH] mtd: properly check all write ioctls for permissions

[Greg Kroah-Hartman]

On Thu, Jul 16, 2020 at 01:53:46PM +0200, Greg Kroah-Hartman wrote:
> When doing a "write" ioctl call, properly check that we have permissions
> to do so before copying anything from userspace or anything else so we
> can "fail fast".  This includes also covering the MEMWRITE ioctl which
> previously missed checking for this.
> 
> Cc: Miquel Raynal <miquel.raynal at bootlin.com>
> Cc: Richard Weinberger <richard at nod.at>
> Cc: Vignesh Raghavendra <vigneshr at ti.com>
> Cc: stable <stable at kernel.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> ---
>  drivers/mtd/mtdchar.c | 54 +++++++++++++++++++++++++++++++++++--------
>  1 file changed, 45 insertions(+), 9 deletions(-)

Any objection to this patch getting into 5.8-final?

I can take this through one of my trees if you all give me an ack :)

thanks,

greg k-h