[PATCH v6] staging: wlan-ng: replace strncpy() with strscpy()

[PATCH v6] staging: wlan-ng: replace strncpy() with strscpy()

[Calvince Otieno]

Checkpatch suggests the use of strscpy() instead of strncpy().
The advantages are that it always adds a NUL terminator and it prevents
a read overflow if the src string is not properly terminated. One
potential disadvantage is that it doesn't zero pad the string like
strncpy() does.
In this code, strscpy() and strncpy() are equivalent and it does not
affect runtime behavior. The string is zeroed on the line before
using memset(). The resulting string was always NUL terminated and
PRISM2_USB_FWFILE is string literal "prism2_ru.fw" so it's NUL
terminated.
However, even though using strscpy() does not fix any bugs, it's
still nicer and makes checkpatch happy.

Signed-off-by: Calvince Otieno <calvncce@gmail.com>
---

Patch version v6:
	Remove extra whitespaces on the patch description text

Patch version v5:
        Removed v1 patch details from the revsion history

Patch version v4:
        Provide a valid description of the patch

Patch version v3:
        Correct the patch subject headline.
        staging: wlan-ng: remove strncpy() use in favor of strscpy()

Patch version v2 :
        Correct implementation of the strscpy()

drivers/staging/wlan-ng/prism2fw.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/wlan-ng/prism2fw.c b/drivers/staging/wlan-ng/prism2fw.c
index 5d03b2b9aab4..3ccd11041646 100644
--- a/drivers/staging/wlan-ng/prism2fw.c
+++ b/drivers/staging/wlan-ng/prism2fw.c
@@ -725,7 +725,7 @@ static int plugimage(struct imgchunk *fchunk, unsigned int nfchunks,

                if (j == -1) {  /* plug the filename */
                        memset(dest, 0, s3plug[i].len);
-                       strncpy(dest, PRISM2_USB_FWFILE, s3plug[i].len - 1);
+                       strscpy(dest, PRISM2_USB_FWFILE, s3plug[i].len);
                } else {	/* plug a PDR */
                        memcpy(dest, &pda->rec[j]->data, s3plug[i].len);
                }

--
Calvince Otieno

Re: [PATCH v6] staging: wlan-ng: replace strncpy() with strscpy()

[Dan Carpenter]

On Fri, Oct 13, 2023 at 02:15:43PM +0300, Calvince Otieno wrote:
> Checkpatch suggests the use of strscpy() instead of strncpy().
> The advantages are that it always adds a NUL terminator and it prevents
> a read overflow if the src string is not properly terminated. One
> potential disadvantage is that it doesn't zero pad the string like
> strncpy() does.
> In this code, strscpy() and strncpy() are equivalent and it does not
> affect runtime behavior. The string is zeroed on the line before
> using memset(). The resulting string was always NUL terminated and
> PRISM2_USB_FWFILE is string literal "prism2_ru.fw" so it's NUL
> terminated.
> However, even though using strscpy() does not fix any bugs, it's
> still nicer and makes checkpatch happy.
> 
> Signed-off-by: Calvince Otieno <calvncce@gmail.com>
> ---

It's still white space damaged and can't apply.  :/  Try save the email
and do `cat raw_email.txt | patch -p1`.

regards,
dan carpenter

Re: [PATCH v6] staging: wlan-ng: replace strncpy() with strscpy()

[Bagas Sanjaya]

On 13/10/2023 18:19, Dan Carpenter wrote:
> On Fri, Oct 13, 2023 at 02:15:43PM +0300, Calvince Otieno wrote:
>> Checkpatch suggests the use of strscpy() instead of strncpy().
>> The advantages are that it always adds a NUL terminator and it prevents
>> a read overflow if the src string is not properly terminated. One
>> potential disadvantage is that it doesn't zero pad the string like
>> strncpy() does.
>> In this code, strscpy() and strncpy() are equivalent and it does not
>> affect runtime behavior. The string is zeroed on the line before
>> using memset(). The resulting string was always NUL terminated and
>> PRISM2_USB_FWFILE is string literal "prism2_ru.fw" so it's NUL
>> terminated.
>> However, even though using strscpy() does not fix any bugs, it's
>> still nicer and makes checkpatch happy.
>>
>> Signed-off-by: Calvince Otieno <calvncce@gmail.com>
>> ---
> 
> It's still white space damaged and can't apply.  :/  Try save the email
> and do `cat raw_email.txt | patch -p1`.
> 

And better yet, use git-send-email(1) to send patches. But don't rush,
as you have sent five versions of this patch today. Please wait for a day
to a week and then reroll.

Thanks.

-- 
An old man doll... just what I always wanted! - Clara