Re: [PATCH] staging: lustre: lustre: libcfs: workitem.c: Cleaning up missing null-terminate after strncpy call

[Kees Cook]

On Sat, Aug 16, 2014 at 4:14 PM, Rickard Strandqvist
<rickard_strandqvist@xxxxxxxxxxxxxxxxxx> wrote:
> 2014-08-12 16:58 GMT+02:00 Kees Cook <keescook@xxxxxxxxxxxx>:
>> On Sat, Aug 9, 2014 at 4:46 PM, Rickard Strandqvist
>> <rickard_strandqvist@xxxxxxxxxxxxxxxxxx> wrote:
>>> Added a guaranteed null-terminate after call to strncpy.
>>>
>>> Signed-off-by: Rickard Strandqvist <rickard_strandqvist@xxxxxxxxxxxxxxxxxx>
>>> ---
>>>  drivers/staging/lustre/lustre/libcfs/workitem.c |    1 +
>>>  1 file changed, 1 insertion(+)
>>>
>>> diff --git a/drivers/staging/lustre/lustre/libcfs/workitem.c b/drivers/staging/lustre/lustre/libcfs/workitem.c
>>> index 0a03bf7..60326f2 100644
>>> --- a/drivers/staging/lustre/lustre/libcfs/workitem.c
>>> +++ b/drivers/staging/lustre/lustre/libcfs/workitem.c
>>> @@ -365,6 +365,7 @@ cfs_wi_sched_create(char *name, struct cfs_cpt_table *cptab,
>>>                 return -ENOMEM;
>>>
>>>         strncpy(sched->ws_name, name, CFS_WS_NAME_LEN);
>>> +       sched->ws_name[CFS_WS_NAME_LEN - 1] = '\0';
>>>         sched->ws_cptab = cptab;
>>>         sched->ws_cpt = cpt;
>>
>> This seems like a place for strlcpy instead?
>>
>> -Kees
>>
>> --
>> Kees Cook
>> Chrome OS Security
>
> Hi Kees
>
> Sure, strlcpy is preferable in many ways if we only can guarantee that
> it is safe.
> I have seldom received so much criticism when I start switching to
> strlcpy, although much of it was justified :)
> Even Linus was getting into the debate.  See more:
>
> https://plus.google.com/111049168280159033135/posts/1amLbuhWbh5
>
>
> I do this only when I'm sure it will not cause any other problems.
> But if you or anyone else can guarantee that in this case, so I'd make
> a new patch with strlcpy.

Ah right, yeah, that limitation is weird. In that case, for your original patch:

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees


-- 
Kees Cook
Chrome OS Security
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