* [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()
@ 2015-07-07 15:48 Jennifer Herbert
2015-07-07 15:51 ` Andrew Cooper
2015-07-07 16:04 ` Ian Jackson
0 siblings, 2 replies; 6+ messages in thread
From: Jennifer Herbert @ 2015-07-07 15:48 UTC (permalink / raw)
To: xen-devel
Cc: wei.liu2, ian.jackson, ian.campbell, Jennifer Herbert,
stefano.stabellini
Unlikely that it may seem localtime_r could fail, which would result in a
null pointer dereference. In this case, it shoud log the errno, (instead of
the date/time), and and continue its logging, as this is still useful.
Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
---
tools/libxc/xtl_logger_stdio.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/tools/libxc/xtl_logger_stdio.c b/tools/libxc/xtl_logger_stdio.c
index d8646e0..5569c50 100644
--- a/tools/libxc/xtl_logger_stdio.c
+++ b/tools/libxc/xtl_logger_stdio.c
@@ -61,10 +61,13 @@ static void stdiostream_vmessage(xentoollog_logger *logger_in,
struct tm lt_buf;
time_t now = time(0);
struct tm *lt= localtime_r(&now, <_buf);
- fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
- lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
- lt->tm_hour, lt->tm_min, lt->tm_sec,
- tzname[!!lt->tm_isdst]);
+ if (lt != NULL)
+ fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
+ lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
+ lt->tm_hour, lt->tm_min, lt->tm_sec,
+ tzname[!!lt->tm_isdst]);
+ else
+ fprintf(lg-f, "[localtime_r failed: %d] ", errno);
}
if (lg->flags & XTL_STDIOSTREAM_SHOW_PID)
fprintf(lg->f, "[%lu] ", (unsigned long)getpid());
--
1.7.10.4
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()
2015-07-07 15:48 [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage() Jennifer Herbert
@ 2015-07-07 15:51 ` Andrew Cooper
2015-07-07 16:05 ` Ian Jackson
2015-07-07 16:08 ` Jennifer Herbert
2015-07-07 16:04 ` Ian Jackson
1 sibling, 2 replies; 6+ messages in thread
From: Andrew Cooper @ 2015-07-07 15:51 UTC (permalink / raw)
To: Jennifer Herbert, xen-devel
Cc: ian.jackson, wei.liu2, ian.campbell, stefano.stabellini
On 07/07/15 16:48, Jennifer Herbert wrote:
> Unlikely that it may seem localtime_r could fail, which would result in a
> null pointer dereference. In this case, it shoud log the errno, (instead of
> the date/time), and and continue its logging, as this is still useful.
>
> Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
> ---
> tools/libxc/xtl_logger_stdio.c | 11 +++++++----
> 1 file changed, 7 insertions(+), 4 deletions(-)
>
> diff --git a/tools/libxc/xtl_logger_stdio.c b/tools/libxc/xtl_logger_stdio.c
> index d8646e0..5569c50 100644
> --- a/tools/libxc/xtl_logger_stdio.c
> +++ b/tools/libxc/xtl_logger_stdio.c
> @@ -61,10 +61,13 @@ static void stdiostream_vmessage(xentoollog_logger *logger_in,
> struct tm lt_buf;
> time_t now = time(0);
> struct tm *lt= localtime_r(&now, <_buf);
> - fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
> - lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
> - lt->tm_hour, lt->tm_min, lt->tm_sec,
> - tzname[!!lt->tm_isdst]);
> + if (lt != NULL)
> + fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
> + lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
> + lt->tm_hour, lt->tm_min, lt->tm_sec,
> + tzname[!!lt->tm_isdst]);
> + else
> + fprintf(lg-f, "[localtime_r failed: %d] ", errno);
lg->f ?
~Andrew
> }
> if (lg->flags & XTL_STDIOSTREAM_SHOW_PID)
> fprintf(lg->f, "[%lu] ", (unsigned long)getpid());
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()
2015-07-07 15:48 [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage() Jennifer Herbert
2015-07-07 15:51 ` Andrew Cooper
@ 2015-07-07 16:04 ` Ian Jackson
1 sibling, 0 replies; 6+ messages in thread
From: Ian Jackson @ 2015-07-07 16:04 UTC (permalink / raw)
To: Jennifer Herbert; +Cc: stefano.stabellini, wei.liu2, ian.campbell, xen-devel
Jennifer Herbert writes ("[PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()"):
> Unlikely that it may seem localtime_r could fail, which would result in a
> null pointer dereference. In this case, it shoud log the errno, (instead of
> the date/time), and and continue its logging, as this is still useful.
Thanks,
Acked-by: Ian Jackson <ian.jackson@eu.citrix.com>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()
2015-07-07 15:51 ` Andrew Cooper
@ 2015-07-07 16:05 ` Ian Jackson
2015-07-07 16:13 ` Jennifer Herbert
2015-07-07 16:08 ` Jennifer Herbert
1 sibling, 1 reply; 6+ messages in thread
From: Ian Jackson @ 2015-07-07 16:05 UTC (permalink / raw)
To: Andrew Cooper
Cc: wei.liu2, stefano.stabellini, Jennifer Herbert, ian.campbell,
xen-devel
Andrew Cooper writes ("Re: [Xen-devel] [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()"):
> On 07/07/15 16:48, Jennifer Herbert wrote:
> > + else
> > + fprintf(lg-f, "[localtime_r failed: %d] ", errno);
>
> lg->f ?
I didn't spot this. I guess the patch wasn't build-tested...
Ian.
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()
2015-07-07 15:51 ` Andrew Cooper
2015-07-07 16:05 ` Ian Jackson
@ 2015-07-07 16:08 ` Jennifer Herbert
1 sibling, 0 replies; 6+ messages in thread
From: Jennifer Herbert @ 2015-07-07 16:08 UTC (permalink / raw)
To: Andrew Cooper, xen-devel
Cc: ian.jackson, wei.liu2, ian.campbell, stefano.stabellini
I guess I didn't build what I thought I built.
V3 coming up
On 07/07/15 16:51, Andrew Cooper wrote:
> On 07/07/15 16:48, Jennifer Herbert wrote:
>> Unlikely that it may seem localtime_r could fail, which would result in a
>> null pointer dereference. In this case, it shoud log the errno, (instead of
>> the date/time), and and continue its logging, as this is still useful.
>>
>> Signed-off-by: Jennifer Herbert <jennifer.herbert@citrix.com>
>> ---
>> tools/libxc/xtl_logger_stdio.c | 11 +++++++----
>> 1 file changed, 7 insertions(+), 4 deletions(-)
>>
>> diff --git a/tools/libxc/xtl_logger_stdio.c b/tools/libxc/xtl_logger_stdio.c
>> index d8646e0..5569c50 100644
>> --- a/tools/libxc/xtl_logger_stdio.c
>> +++ b/tools/libxc/xtl_logger_stdio.c
>> @@ -61,10 +61,13 @@ static void stdiostream_vmessage(xentoollog_logger *logger_in,
>> struct tm lt_buf;
>> time_t now = time(0);
>> struct tm *lt= localtime_r(&now, <_buf);
>> - fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
>> - lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
>> - lt->tm_hour, lt->tm_min, lt->tm_sec,
>> - tzname[!!lt->tm_isdst]);
>> + if (lt != NULL)
>> + fprintf(lg->f, "%04d-%02d-%02d %02d:%02d:%02d %s ",
>> + lt->tm_year+1900, lt->tm_mon+1, lt->tm_mday,
>> + lt->tm_hour, lt->tm_min, lt->tm_sec,
>> + tzname[!!lt->tm_isdst]);
>> + else
>> + fprintf(lg-f, "[localtime_r failed: %d] ", errno);
> lg->f ?
>
> ~Andrew
>
>> }
>> if (lg->flags & XTL_STDIOSTREAM_SHOW_PID)
>> fprintf(lg->f, "[%lu] ", (unsigned long)getpid());
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()
2015-07-07 16:05 ` Ian Jackson
@ 2015-07-07 16:13 ` Jennifer Herbert
0 siblings, 0 replies; 6+ messages in thread
From: Jennifer Herbert @ 2015-07-07 16:13 UTC (permalink / raw)
To: Ian Jackson, Andrew Cooper
Cc: stefano.stabellini, wei.liu2, ian.campbell, xen-devel
On 07/07/15 17:05, Ian Jackson wrote:
> Andrew Cooper writes ("Re: [Xen-devel] [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage()"):
>> On 07/07/15 16:48, Jennifer Herbert wrote:
>>> + else
>>> + fprintf(lg-f, "[localtime_r failed: %d] ", errno);
>> lg->f ?
> I didn't spot this. I guess the patch wasn't build-tested...
>
Not sure what happened there - something was built tested, but I
presumably without this patch.
Sorry about that.
-jenny
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2015-07-07 16:13 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2015-07-07 15:48 [PATCH V2] libxc: Prevent NULL pointer dereference in stdiostream_vmessage() Jennifer Herbert
2015-07-07 15:51 ` Andrew Cooper
2015-07-07 16:05 ` Ian Jackson
2015-07-07 16:13 ` Jennifer Herbert
2015-07-07 16:08 ` Jennifer Herbert
2015-07-07 16:04 ` Ian Jackson
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