On Wed, Jan 30, 2013 at 10:57 AM, walter harms <wharms@xxxxxx> wrote:
>
>
> Am 30.01.2013 09:27, schrieb Dan Carpenter:
>> On Wed, Jan 30, 2013 at 09:15:43AM +0100, walter harms wrote:
>>>
>>>
>>> Am 30.01.2013 08:06, schrieb Dan Carpenter:
>>>> There wasn't any error handling for this kzalloc().
>>>>
>>>> Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
>>>>
>>>> diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
>>>> index c06b8e5..d8293f2 100644
>>>> --- a/drivers/scsi/osd/osd_initiator.c
>>>> +++ b/drivers/scsi/osd/osd_initiator.c
>>>> @@ -144,6 +144,10 @@ static int _osd_get_print_system_info(struct osd_dev *od,
>>>> odi->osdname_len = get_attrs[a].len;
>>>> /* Avoid NULL for memcmp optimization 0-length is good enough */
>>>> odi->osdname = kzalloc(odi->osdname_len + 1, GFP_KERNEL);
>>>> + if (!odi->osdname) {
>>>> + ret = -ENOMEM;
>>>> + goto out;
>>>> + }
>>>> if (odi->osdname_len)
>>>> memcpy(odi->osdname, get_attrs[a].val_ptr, odi->osdname_len);
>>>> OSD_INFO("OSD_NAME [%s]\n", odi->osdname);
>>>> --
>>>
>>> this looks like strdup() ?
>>>
>>
>> Maybe? It's a funny thing going on with the NUL terminator and I
>> don't understand what the comment is about.
>>
>> It appears that normally "get_attrs[a].val_ptr" is a NUL terminated
>> string but "get_attrs[a].len" does not count the terminator.
>>
>> Odd.
>>
> i have no clue what the programmer was thinking. if i read this correct
> osdname is u8 *osdname; so a simple strdup() or strndup() would be ok
> the comment seems to indicate that get_attrs[a].val_ptr could be NULL
> but where is the check ?
> Perhaps they are not using ascii here ? then a memdup(get_attrs[a].len)
> would be better.
There are subtle differences between kstrdup or kmemdup and this implementation.
kmemdup is problematic as get_attrs[a].val_ptr does not contain the
NUL terminator
In the following case:
if get_attrs[a].len == 0
then get_attrs[a].val_ptr == NULL
The end result should be
odi->osdname_len = 0
odi->osdname = kzalloc(1, GFP_KERNEL);
while with kstrdup, odi->osdname will end up being NULL
as it's input arg "s" is NULL.
Benny
>
> re,
> wh
>
>
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