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

[Florian Weimer]

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").

---
Tested on i686-linux-gnu, but only with the glibc test suite.

 sysdeps/unix/sysv/linux/settimeofday.c | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

diff --git a/sysdeps/unix/sysv/linux/settimeofday.c b/sysdeps/unix/sysv/linux/settimeofday.c
index ea45f1d7cb..40529cdeec 100644
--- a/sysdeps/unix/sysv/linux/settimeofday.c
+++ b/sysdeps/unix/sysv/linux/settimeofday.c
@@ -25,14 +25,14 @@
 int
 __settimeofday64 (const struct __timeval64 *tv, const struct timezone *tz)
 {
+  /* The 64-bit interface does support setting the UTC offset.  */
   if (__glibc_unlikely (tz != 0))
     {
       if (tv != 0)
-	{
-	  __set_errno (EINVAL);
-	  return -1;
-	}
-      return __settimezone (tz);
+	__set_errno (EINVAL);
+      else
+	__set_errno (ENOSYS);
+      return -1;
     }
 
   struct __timespec64 ts = timeval64_to_timespec64 (*tv);
@@ -45,8 +45,18 @@ libc_hidden_def (__settimeofday64)
 int
 __settimeofday (const struct timeval *tv, const struct timezone *tz)
 {
+  /* Backwards compatibility for setting the UTC offset.  */
+  if (__glibc_unlikely (tz != 0))
+    {
+      if (tv != 0)
+	{
+	  __set_errno (EINVAL);
+	  return -1;
+	}
+      return __settimezone (tz);
+    }
+
   struct __timeval64 tv64 = valid_timeval_to_timeval64 (*tv);
-
   return __settimeofday64 (&tv64, tz);
 }
 #endif