[PATCH] perf tools: Check for null when copying nsinfo.

[PATCH] perf tools: Check for null when copying nsinfo.

[Benno Evers]

The argument to nsinfo__copy() was assumed to be valid, but some code paths
exist that will lead to NULL being passed.

In particular, running 'perf script -D' on a perf.data file containing an
PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in
the event stream will lead to a segfault.

Since all calling code is already checking for a non-null return value,
just return NULL for this case as well.
---
 tools/perf/util/namespaces.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
index 5be021701f34..cf8bd123cf73 100644
--- a/tools/perf/util/namespaces.c
+++ b/tools/perf/util/namespaces.c
@@ -139,6 +139,9 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
 {
 	struct nsinfo *nnsi;
 
+	if (nsi == NULL)
+		return NULL;
+
 	nnsi = calloc(1, sizeof(*nnsi));
 	if (nnsi != NULL) {
 		nnsi->pid = nsi->pid;
-- 
2.17.1

Re: [PATCH] perf tools: Check for null when copying nsinfo.

[Namhyung Kim]

Hello,

On Thu, Aug 09, 2018 at 11:53:48PM +0200, Benno Evers wrote:
> The argument to nsinfo__copy() was assumed to be valid, but some code paths
> exist that will lead to NULL being passed.
> 
> In particular, running 'perf script -D' on a perf.data file containing an
> PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in
> the event stream will lead to a segfault.
> 
> Since all calling code is already checking for a non-null return value,
> just return NULL for this case as well.

Acked-by: Namhyung Kim <namhyung@kernel.org>

It seems you missed the Signed-off-by though.

Thanks,
Namhyung


> ---
>  tools/perf/util/namespaces.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
> index 5be021701f34..cf8bd123cf73 100644
> --- a/tools/perf/util/namespaces.c
> +++ b/tools/perf/util/namespaces.c
> @@ -139,6 +139,9 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
>  {
>  	struct nsinfo *nnsi;
>  
> +	if (nsi == NULL)
> +		return NULL;
> +
>  	nnsi = calloc(1, sizeof(*nnsi));
>  	if (nnsi != NULL) {
>  		nnsi->pid = nsi->pid;
> -- 
> 2.17.1
> 

Re: [PATCH] perf tools: Check for null when copying nsinfo.

[Arnaldo Carvalho de Melo]

Em Fri, Aug 10, 2018 at 01:55:37PM +0900, Namhyung Kim escreveu:
> Hello,
> 
> On Thu, Aug 09, 2018 at 11:53:48PM +0200, Benno Evers wrote:
> > The argument to nsinfo__copy() was assumed to be valid, but some code paths
> > exist that will lead to NULL being passed.
> > 
> > In particular, running 'perf script -D' on a perf.data file containing an
> > PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in
> > the event stream will lead to a segfault.
> > 
> > Since all calling code is already checking for a non-null return value,
> > just return NULL for this case as well.
> 
> Acked-by: Namhyung Kim <namhyung@kernel.org>
> 
> It seems you missed the Signed-off-by though.

Yeah, please collect Namhyung's Acked-by and provide yours, i.e. your
patch should end with the following lines:


Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Benno Evers <bevers@mesosphere.com>

My git-am scripts will collect the Cc from the e-mail message and add
the Link:  with the Message-id.

Thanks,

- Arnaldo
 
> Thanks,
> Namhyung
> 
> 
> > ---
> >  tools/perf/util/namespaces.c | 3 +++
> >  1 file changed, 3 insertions(+)
> > 
> > diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
> > index 5be021701f34..cf8bd123cf73 100644
> > --- a/tools/perf/util/namespaces.c
> > +++ b/tools/perf/util/namespaces.c
> > @@ -139,6 +139,9 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
> >  {
> >  	struct nsinfo *nnsi;
> >  
> > +	if (nsi == NULL)
> > +		return NULL;
> > +
> >  	nnsi = calloc(1, sizeof(*nnsi));
> >  	if (nnsi != NULL) {
> >  		nnsi->pid = nsi->pid;
> > -- 
> > 2.17.1
> > 

Re: [PATCH] perf tools: Check for null when copying nsinfo.

[Benno Evers]

Haha, sorry, I was following some "how-to-contribute" guide out there, 
but it seems like I missed a step :D I sent out a new version with the 
missing sign-off.


On 10.08.2018 15:18, Arnaldo Carvalho de Melo wrote:
> Em Fri, Aug 10, 2018 at 01:55:37PM +0900, Namhyung Kim escreveu:
>> Hello,
>>
>> On Thu, Aug 09, 2018 at 11:53:48PM +0200, Benno Evers wrote:
>>> The argument to nsinfo__copy() was assumed to be valid, but some code paths
>>> exist that will lead to NULL being passed.
>>>
>>> In particular, running 'perf script -D' on a perf.data file containing an
>>> PERF_RECORD_MMAP event associating the '[vdso]' dso with pid 0 earlier in
>>> the event stream will lead to a segfault.
>>>
>>> Since all calling code is already checking for a non-null return value,
>>> just return NULL for this case as well.
>> Acked-by: Namhyung Kim <namhyung@kernel.org>
>>
>> It seems you missed the Signed-off-by though.
> Yeah, please collect Namhyung's Acked-by and provide yours, i.e. your
> patch should end with the following lines:
>
>
> Acked-by: Namhyung Kim <namhyung@kernel.org>
> Signed-off-by: Benno Evers <bevers@mesosphere.com>
>
> My git-am scripts will collect the Cc from the e-mail message and add
> the Link:  with the Message-id.
>
> Thanks,
>
> - Arnaldo
>   
>> Thanks,
>> Namhyung
>>
>>
>>> ---
>>>   tools/perf/util/namespaces.c | 3 +++
>>>   1 file changed, 3 insertions(+)
>>>
>>> diff --git a/tools/perf/util/namespaces.c b/tools/perf/util/namespaces.c
>>> index 5be021701f34..cf8bd123cf73 100644
>>> --- a/tools/perf/util/namespaces.c
>>> +++ b/tools/perf/util/namespaces.c
>>> @@ -139,6 +139,9 @@ struct nsinfo *nsinfo__copy(struct nsinfo *nsi)
>>>   {
>>>   	struct nsinfo *nnsi;
>>>   
>>> +	if (nsi == NULL)
>>> +		return NULL;
>>> +
>>>   	nnsi = calloc(1, sizeof(*nnsi));
>>>   	if (nnsi != NULL) {
>>>   		nnsi->pid = nsi->pid;
>>> -- 
>>> 2.17.1
>>>