Bug#466491: Proposed patch
tags 466491 tags - moreinfo
tags 466491 tags + patch
retitle 466491 gettimeofday() vDSO on amd64 causes segmentation fault if first argument is NULL
thanks
The attached patch fixes the bug for me. I'm going to send this
upstream as well. Kernel team, any chance we can get this into
a lenny update?
--
+----------------------------------------------------------+
| John Wright <john.wright@hp.com> |
| HP Mission Critical OS Enablement & Solution Test (MOST) |
+----------------------------------------------------------+
>From b972adf1e1436b6c0559f9345abac00a0bb7ed38 Mon Sep 17 00:00:00 2001
From: John Wright <john.wright@hp.com>
Date: Tue, 28 Apr 2009 19:02:42 -0600
Subject: [PATCH] x86: gettimeofday() vDSO: fix segfault when tv == NULL
According to the gettimeofday(2) manual:
If either tv or tz is NULL, the corresponding structure is not
set or returned.
Since it is legal to give NULL as the tv argument, the code should make
sure tv is not NULL before trying to dereference it.
---
arch/x86/vdso/vclock_gettime.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/arch/x86/vdso/vclock_gettime.c b/arch/x86/vdso/vclock_gettime.c
index d9d3582..6a40b78 100644
--- a/arch/x86/vdso/vclock_gettime.c
+++ b/arch/x86/vdso/vclock_gettime.c
@@ -104,11 +104,13 @@ notrace int __vdso_gettimeofday(struct timeval *tv, struct timezone *tz)
{
long ret;
if (likely(gtod->sysctl_enabled && gtod->clock.vread)) {
- BUILD_BUG_ON(offsetof(struct timeval, tv_usec) !=
- offsetof(struct timespec, tv_nsec) ||
- sizeof(*tv) != sizeof(struct timespec));
- do_realtime((struct timespec *)tv);
- tv->tv_usec /= 1000;
+ if (likely(tv != NULL)) {
+ BUILD_BUG_ON(offsetof(struct timeval, tv_usec) !=
+ offsetof(struct timespec, tv_nsec) ||
+ sizeof(*tv) != sizeof(struct timespec));
+ do_realtime((struct timespec *)tv);
+ tv->tv_usec /= 1000;
+ }
if (unlikely(tz != NULL)) {
/* Avoid memcpy. Some old compilers fail to inline it */
tz->tz_minuteswest = gtod->sys_tz.tz_minuteswest;
--
1.6.2.3
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