strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
We expect led->name to be NUL-terminated based on the presence of a
manual NUL-byte assignment.
This NUL-byte assignment was added in Commit daf9669bea30aa22 ("ath5k:
ensure led name is null terminated"). If strscpy() had existed and had
been used back when this code was written then potential bugs and the
need to manually NUL-terminate could have been avoided. Since we now
have the technology, let's use it :)
Considering the above, a suitable replacement is `strscpy` [2] due to
the fact that it guarantees NUL-termination on the destination buffer
without unnecessarily NUL-padding. If NUL-padding is required let's opt
for strscpy_pad().
Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
Link: https://github.com/KSPP/linux/issues/90
Cc: [email protected]
Signed-off-by: Justin Stitt <[email protected]>
---
Note: build-tested only.
Found with: $ rg "strncpy\("
---
drivers/net/wireless/ath/ath5k/led.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/net/wireless/ath/ath5k/led.c b/drivers/net/wireless/ath/ath5k/led.c
index 33e9928af363..439052984796 100644
--- a/drivers/net/wireless/ath/ath5k/led.c
+++ b/drivers/net/wireless/ath/ath5k/led.c
@@ -131,8 +131,7 @@ ath5k_register_led(struct ath5k_hw *ah, struct ath5k_led *led,
int err;
led->ah = ah;
- strncpy(led->name, name, sizeof(led->name));
- led->name[sizeof(led->name)-1] = 0;
+ strscpy(led->name, name, sizeof(led->name));
led->led_dev.name = led->name;
led->led_dev.default_trigger = trigger;
led->led_dev.brightness_set = ath5k_led_brightness_set;
---
base-commit: cbf3a2cb156a2c911d8f38d8247814b4c07f49a2
change-id: 20231013-strncpy-drivers-net-wireless-ath-ath5k-led-c-12487cee93be
Best regards,
--
Justin Stitt <[email protected]>
On 13. 10. 23, 22:53, Justin Stitt wrote:
> strncpy() is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> We expect led->name to be NUL-terminated based on the presence of a
> manual NUL-byte assignment.
>
> This NUL-byte assignment was added in Commit daf9669bea30aa22 ("ath5k:
> ensure led name is null terminated"). If strscpy() had existed and had
> been used back when this code was written then potential bugs and the
> need to manually NUL-terminate could have been avoided. Since we now
> have the technology, let's use it :)
>
> Considering the above, a suitable replacement is `strscpy` [2] due to
> the fact that it guarantees NUL-termination on the destination buffer
> without unnecessarily NUL-padding. If NUL-padding is required let's opt
> for strscpy_pad().
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
LGTM
Reviewed-by: Jiri Slaby <[email protected]>
--
js
suse labs
Justin Stitt <[email protected]> wrote:
> strncpy() is deprecated for use on NUL-terminated destination strings
> [1] and as such we should prefer more robust and less ambiguous string
> interfaces.
>
> We expect led->name to be NUL-terminated based on the presence of a
> manual NUL-byte assignment.
>
> This NUL-byte assignment was added in Commit daf9669bea30aa22 ("ath5k:
> ensure led name is null terminated"). If strscpy() had existed and had
> been used back when this code was written then potential bugs and the
> need to manually NUL-terminate could have been avoided. Since we now
> have the technology, let's use it :)
>
> Considering the above, a suitable replacement is `strscpy` [2] due to
> the fact that it guarantees NUL-termination on the destination buffer
> without unnecessarily NUL-padding. If NUL-padding is required let's opt
> for strscpy_pad().
>
> Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1]
> Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2]
> Link: https://github.com/KSPP/linux/issues/90
> Cc: [email protected]
> Signed-off-by: Justin Stitt <[email protected]>
> Signed-off-by: Kalle Valo <[email protected]>
Patch applied to ath-next branch of ath.git, thanks.
24709752bfe8 wifi: ath5k: replace deprecated strncpy with strscpy
--
https://patchwork.kernel.org/project/linux-wireless/patch/20231013-strncpy-drivers-net-wireless-ath-ath5k-led-c-v1-1-3acb0b5a21f2@google.com/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches