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[PATCH 2/2] linux: clock_settime: Return proper value when passing NULL pointer
- From: Lukasz Majewski <lukma at denx dot de>
- To: Joseph Myers <joseph at codesourcery dot com>, Paul Eggert <eggert at cs dot ucla dot edu>
- Cc: Alistair Francis <alistair23 at gmail dot com>, Alistair Francis <alistair dot francis at wdc dot com>, GNU C Library <libc-alpha at sourceware dot org>, Adhemerval Zanella <adhemerval dot zanella at linaro dot org>, Florian Weimer <fweimer at redhat dot com>, Florian Weimer <fw at deneb dot enyo dot de>, Zack Weinberg <zackw at panix dot com>, Carlos O'Donell <carlos at redhat dot com>, Lukasz Majewski <lukma at denx dot de>
- Date: Fri, 8 Nov 2019 16:33:44 +0100
- Subject: [PATCH 2/2] linux: clock_settime: Return proper value when passing NULL pointer
- References: <20191108153344.10949-1-lukma@denx.de>
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