Re: [PATCH] sysctl: remove duplicate UINT_MAX check on do_proc_douintvec_conv()

From: Kees Cook
Date: Tue Sep 19 2017 - 17:52:36 EST


On Tue, Sep 19, 2017 at 12:29 AM, Luis R. Rodriguez <mcgrof@xxxxxxxxxx> wrote:
> do_proc_douintvec_conv() has two UINT_MAX checks, we can remove one.
> This has no functional changes other than fixing a compiler warning:
>
> kernel/sysctl.c:2190]: (warning) Identical condition '*lvalp>UINT_MAX', second condition is always false
>
> Reported-by: David Binderman <dcb314@xxxxxxxxxxx>
> Signed-off-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx>

Fixes: 4f2fec00afa60 ("sysctl: simplify unsigned int support")
Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
> kernel/sysctl.c | 2 --
> 1 file changed, 2 deletions(-)
>
> diff --git a/kernel/sysctl.c b/kernel/sysctl.c
> index 4c08ed4a379e..0da31bbbff18 100644
> --- a/kernel/sysctl.c
> +++ b/kernel/sysctl.c
> @@ -2181,8 +2181,6 @@ static int do_proc_douintvec_conv(unsigned long *lvalp,
> int write, void *data)
> {
> if (write) {
> - if (*lvalp > UINT_MAX)
> - return -EINVAL;
> if (*lvalp > UINT_MAX)
> return -EINVAL;
> *valp = *lvalp;
> --
> 2.14.0
>



--
Kees Cook
Pixel Security