Re: dev_ifname32() fails on 32->64bit calls in copy_in_user().

[ebiederm@xmission.com (Eric W. Biederman)]

Benjamin Herrenschmidt <benh@kernel.crashing.org> writes:

> Bug is in the new dev_ifname32:
>
> 	uifr = compat_alloc_user_space(sizeof(struct ifreq));
> 	if (copy_in_user(uifr, compat_ptr(arg), sizeof(struct ifreq32)));
> 		return -EFAULT;
>
> There's a stray ";" after the if statement, that was obviously not
> tested :-)

Grr sorry about that, and thanks for catching this.

Eric


> This fixes it here (tested):
> ----------------------------------------------------------------------------
> [PATCH] Fix new dev_ifname32 returning -EFAULT
>
> A stray semicolon slipped in the patch that updated dev_ifname32 to
> not be inline, causing it to always return -EFAULT. This fixes it.
>
> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> ---
>
> Index: linux-work/fs/compat_ioctl.c
> ===================================================================
> --- linux-work.orig/fs/compat_ioctl.c	2007-10-31 13:30:42.000000000 +1100
> +++ linux-work/fs/compat_ioctl.c	2007-10-31 13:30:46.000000000 +1100
> @@ -322,7 +322,7 @@ static int dev_ifname32(unsigned int fd,
>  	int err;
>  
>  	uifr = compat_alloc_user_space(sizeof(struct ifreq));
> -	if (copy_in_user(uifr, compat_ptr(arg), sizeof(struct ifreq32)));
> +	if (copy_in_user(uifr, compat_ptr(arg), sizeof(struct ifreq32)))
>  		return -EFAULT;
>  
>  	err = sys_ioctl(fd, SIOCGIFNAME, (unsigned long)uifr);