On 10/05/2017 02:35 PM, Piasecki, JacekX wrote:
-----Original Message-----
From: Maxime Coquelin [mailto:maxime.coque...@redhat.com]
Sent: Monday, 2 October, 2017 17:07
To: Jastrzebski, MichalX K <michalx.k.jastrzeb...@intel.com>; 
y...@fridaylinux.org
Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.j...@intel.com>; Piasecki, JacekX 
<jacekx.piase...@intel.com>; Liu, Changpeng <changpeng....@intel.com>; sta...@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-boun...@dpdk.org] On Behalf Of Michal
Jastrzebski
Sent: Friday, September 22, 2017 3:08 PM
To: y...@fridaylinux.org; maxime.coque...@redhat.com
Cc: dev@dpdk.org; Jain, Deepak K <deepak.k.j...@intel.com>; Piasecki,
JacekX <jacekx.piase...@intel.com>; Liu, Changpeng
<changpeng....@intel.com>; sta...@dpdk.org
Subject: [dpdk-dev] [PATCH] examples/vhost_scsi: fix buffer not
terminated

From: Jacek Piasecki <jacekx.piase...@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....@intel.com
Cc: sta...@dpdk.org

Signed-off-by: Jacek Piasecki <jacekx.piase...@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.

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