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 <[email protected]>
---
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
On Fri, Oct 13, 2023 at 01:21:21PM +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 <[email protected]>
> ---
> Patch version v5:
> Removed v1 patch details from the revsion history
This patch doesn't apply correctly. It has been white space damaged
for some reason. Tabs replaced with spaces. Read
Documentation/process/email-clients.rst. Hopefully the first paragraph
convinces you to just use git to send patchs and you can skip the rest
of the document.
I try to catch these sorts of mistakes earlier instead of making you
send a v6 but I thought the issue was the v1. Sorry about that. The
good news is that now you can delete the extra space character Julia
mentioned.
regards,
dan carpenter