[PATCH] mtd: require write permissions for locking and badblock ioctls

[Greg Kroah-Hartman]

On Wed, Mar 03, 2021 at 04:57:35PM +0100, Michael Walle wrote:
> MEMLOCK, MEMUNLOCK and OTPLOCK modify protection bits. Thus require
> write permission. Depending on the hardware MEMLOCK might even be
> write-once, e.g. for SPI-NOR flashes with their WP# tied to GND. OTPLOCK
> is always write-once.
> 
> MEMSETBADBLOCK modifies the bad block table.
> 
> Fixes: f7e6b19bc764 ("mtd: properly check all write ioctls for permissions")
> Signed-off-by: Michael Walle <michael at walle.cc>
> ---
>  drivers/mtd/mtdchar.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)

Thanks for auditing the rest of these from my original patch.  If this
is ok with userspace tools, it's fine with me, but I don't even have
this hardware to test with :)

Reviewed-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>