[PATCH 2/2] linux: clock_settime: Return proper value when passing NULL pointer

[Lukasz Majewski]

When in __clock_settime function (__TIMESIZE != 64) the const struct
timespec's *tp pointer is NULL, the Linux kernel syscall returns
-EFAULT.
Without this patch the glibc crashes (when dereferencing NULL pointer)
as the Linux kernel syscall is not reached at all.

There is no need for such check in the __clock_settime64, as this
pointer either goes directly to Linux kernel or the pointer to local
copy is used (ts64).
---
 sysdeps/unix/sysv/linux/clock_settime.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/sysdeps/unix/sysv/linux/clock_settime.c b/sysdeps/unix/sysv/linux/clock_settime.c
index 6706dbb31f..e358a18998 100644
--- a/sysdeps/unix/sysv/linux/clock_settime.c
+++ b/sysdeps/unix/sysv/linux/clock_settime.c
@@ -51,7 +51,14 @@ __clock_settime64 (clockid_t clock_id, const struct __timespec64 *tp)
 int
 __clock_settime (clockid_t clock_id, const struct timespec *tp)
 {
-  struct __timespec64 ts64 = valid_timespec_to_timespec64 (*tp);
+  struct __timespec64 ts64;
+
+  if (tp == NULL)
+    {
+      __set_errno (EFAULT);
+      return -1;
+    }
+  ts64 = valid_timespec_to_timespec64 (*tp);
 
   return __clock_settime64 (clock_id, &ts64);
 }
-- 
2.20.1