Re: [PATCH] tty/vt/keyboard: use memdup_user().

From: Samuel Thibault
Date: Fri May 20 2016 - 08:27:13 EST


Muhammad Falak R Wani, on Fri 20 May 2016 17:53:28 +0530, wrote:
> Use memdup_user to duplicate a memory region from user-space to
> kernel-space, instead of open coding using kmalloc & copy_from_user.
>
> Signed-off-by: Muhammad Falak R Wani <falakreyaz@xxxxxxxxx>

Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>

> ---
> drivers/tty/vt/keyboard.c | 14 ++++----------
> 1 file changed, 4 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/tty/vt/keyboard.c b/drivers/tty/vt/keyboard.c
> index f973bfc..698ea43 100644
> --- a/drivers/tty/vt/keyboard.c
> +++ b/drivers/tty/vt/keyboard.c
> @@ -1745,16 +1745,10 @@ int vt_do_diacrit(unsigned int cmd, void __user *udp, int perm)
> return -EINVAL;
>
> if (ct) {
> - buf = kmalloc(ct * sizeof(struct kbdiacruc),
> - GFP_KERNEL);
> - if (buf == NULL)
> - return -ENOMEM;
> -
> - if (copy_from_user(buf, a->kbdiacruc,
> - ct * sizeof(struct kbdiacruc))) {
> - kfree(buf);
> - return -EFAULT;
> - }
> + buf = memdup_user(a->kbdiacruc,
> + ct * sizeof(struct kbdiacruc));
> + if (IS_ERR(buf))
> + return PTR_ERR(buf);
> }
> spin_lock_irqsave(&kbd_event_lock, flags);
> if (ct)
> --
> 1.9.1
>

--
Samuel
(03:13:14) <j> bon
(03:13:19) <j> il est tard :p
(03:13:25) <g> c'est l'heure de manger
(03:13:38) <j> hm j'ai mangé à 1h moi, j'ai des horaires raisonnables