[PATCH v2] Linux: Fix UTC offset setting in settimeofday for __TIMESIZE != 64

[Adhemerval Zanella]

On 30/06/2020 15:45, Florian Weimer wrote:
> The time argument is NULL in this case, and attempt to convert it
> leads to a null pointer dereference.
> 
> This fixes commit d2e3b697da2433c08702f95c76458c51545c3df1
> ("y2038: linux: Provide __settimeofday64 implementation").

LGTM, thanks.

Reviwed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> 
> ---
> v2: Add just a null pointer check.  Tested on x86_64-linux-gnu and
>     i686-linux-gnu.
> 
>  sysdeps/unix/sysv/linux/settimeofday.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/sysdeps/unix/sysv/linux/settimeofday.c b/sysdeps/unix/sysv/linux/settimeofday.c
> index ea45f1d7cb..6f4bc7ef3c 100644
> --- a/sysdeps/unix/sysv/linux/settimeofday.c
> +++ b/sysdeps/unix/sysv/linux/settimeofday.c
> @@ -25,6 +25,7 @@
>  int
>  __settimeofday64 (const struct __timeval64 *tv, const struct timezone *tz)
>  {
> +  /* Backwards compatibility for setting the UTC offset.  */
>    if (__glibc_unlikely (tz != 0))
>      {
>        if (tv != 0)
> @@ -45,9 +46,13 @@ libc_hidden_def (__settimeofday64)
>  int
>  __settimeofday (const struct timeval *tv, const struct timezone *tz)
>  {
> -  struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);
> -
> -  return __settimeofday64 (&tv64, tz);
> +  if (__glibc_unlikely (tv == NULL))
> +      return __settimeofday64 (NULL, tz);

Indentation seems off here.

> +  else
> +    {
> +      struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);
> +      return __settimeofday64 (&tv64, tz);
> +    }
>  }
>  #endif
>  weak_alias (__settimeofday, settimeofday);
>