diff mbox

[dpdk-dev] examples/vhost_scsi: fix buffer not terminated

Message ID 20170922130734.7256-1-michalx.k.jastrzebski@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Yuanhan Liu
Headers

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Michal Jastrzebski Sept. 22, 2017, 1:07 p.m. UTC 
  From: Jacek Piasecki <jacekx.piasecki@intel.com>

Fix size of buffer in strcpy. There was possible to get
not terminated string after copy operation.

Coverity issue: 158631
Fixes: db75c7af19bb ("examples/vhost_scsi: introduce a new sample app")
Cc: changpeng.liu@intel.com
Cc: stable@dpdk.org

Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>
---
 examples/vhost_scsi/scsi.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Michal Jastrzebski Oct. 2, 2017, 1:50 p.m. UTC | #1 
> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michal Jastrzebski
> Sent: Friday, September 22, 2017 3:08 PM
> To: yliu@fridaylinux.org; maxime.coquelin@redhat.com
> Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki,
> JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng
> <changpeng.liu@intel.com>; stable@dpdk.org
> Subject: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not terminated
> 
> From: Jacek Piasecki <jacekx.piasecki@intel.com>
> 
> Fix size of buffer in strcpy. There was possible to get
> not terminated string after copy operation.
> 
> Coverity issue: 158631
> Fixes: db75c7af19bb ("examples/vhost_scsi: introduce a new sample app")
> Cc: changpeng.liu@intel.com
> Cc: stable@dpdk.org
> 
> Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>
> ---
>  examples/vhost_scsi/scsi.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/examples/vhost_scsi/scsi.c b/examples/vhost_scsi/scsi.c
> index 54d3104..de9639a 100644
> --- a/examples/vhost_scsi/scsi.c
> +++ b/examples/vhost_scsi/scsi.c
> @@ -307,7 +307,8 @@
>  		strncpy((char *)inqdata->t10_vendor_id, "INTEL", 8);
> 
>  		/* PRODUCT IDENTIFICATION */
> -		strncpy((char *)inqdata->product_id, bdev->product_name,
> 16);
> +		strncpy((char *)inqdata->product_id, bdev->product_name,
> +				ARRAY_SIZE(inqdata->product_id) - 1);
> 
>  		/* PRODUCT REVISION LEVEL */
>  		strncpy((char *)inqdata->product_rev, "0001", 4);
> --
> 1.9.1

Hi Yu / Maxime,
I would like to ask for a feedback regarding proposed fix.
If everything is ok with it, please send acked-by.

Best regards
Michal.
Maxime Coquelin Oct. 2, 2017, 3:07 p.m. UTC | #2 
On 10/02/2017 03:50 PM, Jastrzebski, MichalX K wrote:
>> -----Original Message-----
>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michal Jastrzebski
>> Sent: Friday, September 22, 2017 3:08 PM
>> To: yliu@fridaylinux.org; maxime.coquelin@redhat.com
>> Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki,
>> JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng
>> <changpeng.liu@intel.com>; stable@dpdk.org
>> Subject: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not terminated
>>
>> From: Jacek Piasecki <jacekx.piasecki@intel.com>
>>
>> Fix size of buffer in strcpy. There was possible to get
>> not terminated string after copy operation.
>>
>> Coverity issue: 158631
>> Fixes: db75c7af19bb ("examples/vhost_scsi: introduce a new sample app")
>> Cc: changpeng.liu@intel.com
>> Cc: stable@dpdk.org
>>
>> Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>
>> ---
>>   examples/vhost_scsi/scsi.c | 3 ++-
>>   1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/examples/vhost_scsi/scsi.c b/examples/vhost_scsi/scsi.c
>> index 54d3104..de9639a 100644
>> --- a/examples/vhost_scsi/scsi.c
>> +++ b/examples/vhost_scsi/scsi.c
>> @@ -307,7 +307,8 @@
>>   		strncpy((char *)inqdata->t10_vendor_id, "INTEL", 8);
>>
>>   		/* PRODUCT IDENTIFICATION */
>> -		strncpy((char *)inqdata->product_id, bdev->product_name,
>> 16);
>> +		strncpy((char *)inqdata->product_id, bdev->product_name,
>> +				ARRAY_SIZE(inqdata->product_id) - 1);

Does it assume that product_id is memzero'ed before?
IIUC strncpy manpage, it wouldn't protect against non-null terminated
strings if it is not the case:

"
        A simple implementation of strncpy() might be:

            char *
            strncpy(char *dest, const char *src, size_t n)
            {
                size_t i;

                for (i = 0; i < n && src[i] != '\0'; i++)
                    dest[i] = src[i];
                for ( ; i < n; i++)
                    dest[i] = '\0';

                return dest;
            }
"

Cheers,
Maxime

>>
>>   		/* PRODUCT REVISION LEVEL */
>>   		strncpy((char *)inqdata->product_rev, "0001", 4);
>> --
>> 1.9.1
> 
> Hi Yu / Maxime,
> I would like to ask for a feedback regarding proposed fix.
> If everything is ok with it, please send acked-by.
> 
> Best regards
> Michal.
>
Jacek Piasecki Oct. 5, 2017, 12:35 p.m. UTC | #3 
-----Original Message-----
From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com] 

Sent: Monday, 2 October, 2017 17:07
To: Jastrzebski, MichalX K <michalx.k.jastrzebski@intel.com>; yliu@fridaylinux.org
Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki, JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng <changpeng.liu@intel.com>; stable@dpdk.org
Subject: Re: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not terminated



On 10/02/2017 03:50 PM, Jastrzebski, MichalX K wrote:
>> -----Original Message-----

>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michal 

>> Jastrzebski

>> Sent: Friday, September 22, 2017 3:08 PM

>> To: yliu@fridaylinux.org; maxime.coquelin@redhat.com

>> Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki, 

>> JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng 

>> <changpeng.liu@intel.com>; stable@dpdk.org

>> Subject: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not 

>> terminated

>>

>> From: Jacek Piasecki <jacekx.piasecki@intel.com>

>>

>> Fix size of buffer in strcpy. There was possible to get not 

>> terminated string after copy operation.

>>

>> Coverity issue: 158631

>> Fixes: db75c7af19bb ("examples/vhost_scsi: introduce a new sample 

>> app")

>> Cc: changpeng.liu@intel.com

>> Cc: stable@dpdk.org

>>

>> Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>

>> ---

>>   examples/vhost_scsi/scsi.c | 3 ++-

>>   1 file changed, 2 insertions(+), 1 deletion(-)

>>

>> diff --git a/examples/vhost_scsi/scsi.c b/examples/vhost_scsi/scsi.c 

>> index 54d3104..de9639a 100644

>> --- a/examples/vhost_scsi/scsi.c

>> +++ b/examples/vhost_scsi/scsi.c

>> @@ -307,7 +307,8 @@

>>   		strncpy((char *)inqdata->t10_vendor_id, "INTEL", 8);

>>

>>   		/* PRODUCT IDENTIFICATION */

>> -		strncpy((char *)inqdata->product_id, bdev->product_name,

>> 16);

>> +		strncpy((char *)inqdata->product_id, bdev->product_name,

>> +				ARRAY_SIZE(inqdata->product_id) - 1);


Does it assume that product_id is memzero'ed before?
IIUC strncpy manpage, it wouldn't protect against non-null terminated strings if it is not the case:

Yes, I assumed that this area is zeroed before strncpy. Earlier there is a casting from *task to *inqdata (*task is zmalloced).
To be sure that the destination area is clear I propose to add:
memset(inqdata->product_id, 0, ARRAY_SIZE(inqdata->product_id));
before strncpy. Would that be OK?

Regards,
Jacek

>>

>>   		/* PRODUCT REVISION LEVEL */

>>   		strncpy((char *)inqdata->product_rev, "0001", 4);

>> --

>> 1.9.1

> 

> Hi Yu / Maxime,

> I would like to ask for a feedback regarding proposed fix.

> If everything is ok with it, please send acked-by.

> 

> Best regards

> Michal.

>
Maxime Coquelin Oct. 5, 2017, 12:42 p.m. UTC | #4 
On 10/05/2017 02:35 PM, Piasecki, JacekX wrote:
> -----Original Message-----
> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
> Sent: Monday, 2 October, 2017 17:07
> To: Jastrzebski, MichalX K <michalx.k.jastrzebski@intel.com>; yliu@fridaylinux.org
> Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki, JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng <changpeng.liu@intel.com>; stable@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not terminated
> 
> 
> 
> On 10/02/2017 03:50 PM, Jastrzebski, MichalX K wrote:
>>> -----Original Message-----
>>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michal
>>> Jastrzebski
>>> Sent: Friday, September 22, 2017 3:08 PM
>>> To: yliu@fridaylinux.org; maxime.coquelin@redhat.com
>>> Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki,
>>> JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng
>>> <changpeng.liu@intel.com>; stable@dpdk.org
>>> Subject: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not
>>> terminated
>>>
>>> From: Jacek Piasecki <jacekx.piasecki@intel.com>
>>>
>>> Fix size of buffer in strcpy. There was possible to get not
>>> terminated string after copy operation.
>>>
>>> Coverity issue: 158631
>>> Fixes: db75c7af19bb ("examples/vhost_scsi: introduce a new sample
>>> app")
>>> Cc: changpeng.liu@intel.com
>>> Cc: stable@dpdk.org
>>>
>>> Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>
>>> ---
>>>    examples/vhost_scsi/scsi.c | 3 ++-
>>>    1 file changed, 2 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/examples/vhost_scsi/scsi.c b/examples/vhost_scsi/scsi.c
>>> index 54d3104..de9639a 100644
>>> --- a/examples/vhost_scsi/scsi.c
>>> +++ b/examples/vhost_scsi/scsi.c
>>> @@ -307,7 +307,8 @@
>>>    		strncpy((char *)inqdata->t10_vendor_id, "INTEL", 8);
>>>
>>>    		/* PRODUCT IDENTIFICATION */
>>> -		strncpy((char *)inqdata->product_id, bdev->product_name,
>>> 16);
>>> +		strncpy((char *)inqdata->product_id, bdev->product_name,
>>> +				ARRAY_SIZE(inqdata->product_id) - 1);
> 
> Does it assume that product_id is memzero'ed before?
> IIUC strncpy manpage, it wouldn't protect against non-null terminated strings if it is not the case:
> 
> Yes, I assumed that this area is zeroed before strncpy. Earlier there is a casting from *task to *inqdata (*task is zmalloced).
Ok. I think the assumption is dangerous.

> To be sure that the destination area is clear I propose to add:
> memset(inqdata->product_id, 0, ARRAY_SIZE(inqdata->product_id));
> before strncpy. Would that be OK?

Or call strncpy with ARRAY_SIZE(inqdata->product_id) as max length,
and then do
inqdata->product_id[ARRAY_SIZE(inqdata->product_id) - 1] = '\0';

Regards,
Maxime
> 
> Regards,
> Jacek
> 
>>>
>>>    		/* PRODUCT REVISION LEVEL */
>>>    		strncpy((char *)inqdata->product_rev, "0001", 4);
>>> --
>>> 1.9.1
>>
>> Hi Yu / Maxime,
>> I would like to ask for a feedback regarding proposed fix.
>> If everything is ok with it, please send acked-by.
>>
>> Best regards
>> Michal.
>>
Bruce Richardson Oct. 5, 2017, 1:01 p.m. UTC | #5 
On Thu, Oct 05, 2017 at 02:42:24PM +0200, Maxime Coquelin wrote:
> 
> 
> On 10/05/2017 02:35 PM, Piasecki, JacekX wrote:
> > -----Original Message-----
> > From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
> > Sent: Monday, 2 October, 2017 17:07
> > To: Jastrzebski, MichalX K <michalx.k.jastrzebski@intel.com>; yliu@fridaylinux.org
> > Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki, JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng <changpeng.liu@intel.com>; stable@dpdk.org
> > Subject: Re: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not terminated
> > 
> > 
> > 
> > On 10/02/2017 03:50 PM, Jastrzebski, MichalX K wrote:
> > > > -----Original Message-----
> > > > From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michal
> > > > Jastrzebski
> > > > Sent: Friday, September 22, 2017 3:08 PM
> > > > To: yliu@fridaylinux.org; maxime.coquelin@redhat.com
> > > > Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki,
> > > > JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng
> > > > <changpeng.liu@intel.com>; stable@dpdk.org
> > > > Subject: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not
> > > > terminated
> > > > 
> > > > From: Jacek Piasecki <jacekx.piasecki@intel.com>
> > > > 
> > > > Fix size of buffer in strcpy. There was possible to get not
> > > > terminated string after copy operation.
> > > > 
> > > > Coverity issue: 158631
> > > > Fixes: db75c7af19bb ("examples/vhost_scsi: introduce a new sample
> > > > app")
> > > > Cc: changpeng.liu@intel.com
> > > > Cc: stable@dpdk.org
> > > > 
> > > > Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>
> > > > ---
> > > >    examples/vhost_scsi/scsi.c | 3 ++-
> > > >    1 file changed, 2 insertions(+), 1 deletion(-)
> > > > 
> > > > diff --git a/examples/vhost_scsi/scsi.c b/examples/vhost_scsi/scsi.c
> > > > index 54d3104..de9639a 100644
> > > > --- a/examples/vhost_scsi/scsi.c
> > > > +++ b/examples/vhost_scsi/scsi.c
> > > > @@ -307,7 +307,8 @@
> > > >    		strncpy((char *)inqdata->t10_vendor_id, "INTEL", 8);
> > > > 
> > > >    		/* PRODUCT IDENTIFICATION */
> > > > -		strncpy((char *)inqdata->product_id, bdev->product_name,
> > > > 16);
> > > > +		strncpy((char *)inqdata->product_id, bdev->product_name,
> > > > +				ARRAY_SIZE(inqdata->product_id) - 1);
> > 
> > Does it assume that product_id is memzero'ed before?
> > IIUC strncpy manpage, it wouldn't protect against non-null terminated strings if it is not the case:
> > 
> > Yes, I assumed that this area is zeroed before strncpy. Earlier there is a casting from *task to *inqdata (*task is zmalloced).
> Ok. I think the assumption is dangerous.
> 
> > To be sure that the destination area is clear I propose to add:
> > memset(inqdata->product_id, 0, ARRAY_SIZE(inqdata->product_id));
> > before strncpy. Would that be OK?
> 
> Or call strncpy with ARRAY_SIZE(inqdata->product_id) as max length,
> and then do
> inqdata->product_id[ARRAY_SIZE(inqdata->product_id) - 1] = '\0';
> 
> Regards,
> Maxime
> > 
Or use snprintf instead of strncpy, as we do in many places in DPDK.
Still only one line of code, with nice null-termination, and truncation
semantics.

/Bruce
Maxime Coquelin Oct. 5, 2017, 1:02 p.m. UTC | #6 
On 10/05/2017 03:01 PM, Bruce Richardson wrote:
> On Thu, Oct 05, 2017 at 02:42:24PM +0200, Maxime Coquelin wrote:
>>
>>
>> On 10/05/2017 02:35 PM, Piasecki, JacekX wrote:
>>> -----Original Message-----
>>> From: Maxime Coquelin [mailto:maxime.coquelin@redhat.com]
>>> Sent: Monday, 2 October, 2017 17:07
>>> To: Jastrzebski, MichalX K <michalx.k.jastrzebski@intel.com>; yliu@fridaylinux.org
>>> Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki, JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng <changpeng.liu@intel.com>; stable@dpdk.org
>>> Subject: Re: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not terminated
>>>
>>>
>>>
>>> On 10/02/2017 03:50 PM, Jastrzebski, MichalX K wrote:
>>>>> -----Original Message-----
>>>>> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Michal
>>>>> Jastrzebski
>>>>> Sent: Friday, September 22, 2017 3:08 PM
>>>>> To: yliu@fridaylinux.org; maxime.coquelin@redhat.com
>>>>> Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.jain@intel.com>; Piasecki,
>>>>> JacekX <jacekx.piasecki@intel.com>; Liu, Changpeng
>>>>> <changpeng.liu@intel.com>; stable@dpdk.org
>>>>> Subject: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not
>>>>> terminated
>>>>>
>>>>> From: Jacek Piasecki <jacekx.piasecki@intel.com>
>>>>>
>>>>> Fix size of buffer in strcpy. There was possible to get not
>>>>> terminated string after copy operation.
>>>>>
>>>>> Coverity issue: 158631
>>>>> Fixes: db75c7af19bb ("examples/vhost_scsi: introduce a new sample
>>>>> app")
>>>>> Cc: changpeng.liu@intel.com
>>>>> Cc: stable@dpdk.org
>>>>>
>>>>> Signed-off-by: Jacek Piasecki <jacekx.piasecki@intel.com>
>>>>> ---
>>>>>     examples/vhost_scsi/scsi.c | 3 ++-
>>>>>     1 file changed, 2 insertions(+), 1 deletion(-)
>>>>>
>>>>> diff --git a/examples/vhost_scsi/scsi.c b/examples/vhost_scsi/scsi.c
>>>>> index 54d3104..de9639a 100644
>>>>> --- a/examples/vhost_scsi/scsi.c
>>>>> +++ b/examples/vhost_scsi/scsi.c
>>>>> @@ -307,7 +307,8 @@
>>>>>     		strncpy((char *)inqdata->t10_vendor_id, "INTEL", 8);
>>>>>
>>>>>     		/* PRODUCT IDENTIFICATION */
>>>>> -		strncpy((char *)inqdata->product_id, bdev->product_name,
>>>>> 16);
>>>>> +		strncpy((char *)inqdata->product_id, bdev->product_name,
>>>>> +				ARRAY_SIZE(inqdata->product_id) - 1);
>>>
>>> Does it assume that product_id is memzero'ed before?
>>> IIUC strncpy manpage, it wouldn't protect against non-null terminated strings if it is not the case:
>>>
>>> Yes, I assumed that this area is zeroed before strncpy. Earlier there is a casting from *task to *inqdata (*task is zmalloced).
>> Ok. I think the assumption is dangerous.
>>
>>> To be sure that the destination area is clear I propose to add:
>>> memset(inqdata->product_id, 0, ARRAY_SIZE(inqdata->product_id));
>>> before strncpy. Would that be OK?
>>
>> Or call strncpy with ARRAY_SIZE(inqdata->product_id) as max length,
>> and then do
>> inqdata->product_id[ARRAY_SIZE(inqdata->product_id) - 1] = '\0';
>>
>> Regards,
>> Maxime
>>>
> Or use snprintf instead of strncpy, as we do in many places in DPDK.
> Still only one line of code, with nice null-termination, and truncation
> semantics.

+1

> /Bruce
>
diff mbox

Patch

diff --git a/examples/vhost_scsi/scsi.c b/examples/vhost_scsi/scsi.c
index 54d3104..de9639a 100644
--- a/examples/vhost_scsi/scsi.c
+++ b/examples/vhost_scsi/scsi.c
@@ -307,7 +307,8 @@ 
 		strncpy((char *)inqdata->t10_vendor_id, "INTEL", 8);
 
 		/* PRODUCT IDENTIFICATION */
-		strncpy((char *)inqdata->product_id, bdev->product_name, 16);
+		strncpy((char *)inqdata->product_id, bdev->product_name,
+				ARRAY_SIZE(inqdata->product_id) - 1);
 
 		/* PRODUCT REVISION LEVEL */
 		strncpy((char *)inqdata->product_rev, "0001", 4);