2022-12-05 11:37:17

by Yang Yang

Subject: [PATCH linux-next v2] accessibility: speakup: use strscpy() to instead of strncpy()

From: Xu Panda <[email protected]>

The implementation of strscpy() is more robust and safer.
That's now the recommended way to copy NUL terminated strings.
---
change for v2
- fix the mistake of eating one character when len > 250,
thanks to Samuel Thibault.
---

Signed-off-by: Xu Panda <[email protected]>
Signed-off-by: Yang Yang <[email protected]>
Signed-off-by: Samuel Thibault <[email protected]>
---
drivers/accessibility/speakup/kobjects.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/accessibility/speakup/kobjects.c b/drivers/accessibility/speakup/kobjects.c
index a7522d409802..c1ef48280f3c 100644
--- a/drivers/accessibility/speakup/kobjects.c
+++ b/drivers/accessibility/speakup/kobjects.c
@@ -426,8 +426,7 @@ static ssize_t synth_direct_store(struct kobject *kobj,
spin_lock_irqsave(&speakup_info.spinlock, flags);
while (len > 0) {
bytes = min_t(size_t, len, 250);
- strncpy(tmp, ptr, bytes);
- tmp[bytes] = '\0';
+ strscpy(tmp, ptr, bytes + 1);
string_unescape_any_inplace(tmp);
synth_printf("%s", tmp);
ptr += bytes;
--
2.15.2

2022-12-05 13:08:19

by Samuel Thibault

Subject: Re: [PATCH linux-next v2] accessibility: speakup: use strscpy() to instead of strncpy()

[email protected], le lun. 05 déc. 2022 19:28:46 +0800, a ecrit:
> From: Xu Panda <[email protected]>
>
> The implementation of strscpy() is more robust and safer.
> That's now the recommended way to copy NUL terminated strings.
> ---
> change for v2
> - fix the mistake of eating one character when len > 250,
> thanks to Samuel Thibault.
> ---
>
> Signed-off-by: Xu Panda <[email protected]>
> Signed-off-by: Yang Yang <[email protected]>
> Signed-off-by: Samuel Thibault <[email protected]>

It's not really a signed-off from my side, I just did a review :)

but with that version,

Reviewed-by: Samuel Thibault <[email protected]>

> ---
> drivers/accessibility/speakup/kobjects.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/accessibility/speakup/kobjects.c b/drivers/accessibility/speakup/kobjects.c
> index a7522d409802..c1ef48280f3c 100644
> --- a/drivers/accessibility/speakup/kobjects.c
> +++ b/drivers/accessibility/speakup/kobjects.c
> @@ -426,8 +426,7 @@ static ssize_t synth_direct_store(struct kobject *kobj,
> spin_lock_irqsave(&speakup_info.spinlock, flags);
> while (len > 0) {
> bytes = min_t(size_t, len, 250);
> - strncpy(tmp, ptr, bytes);
> - tmp[bytes] = '\0';
> + strscpy(tmp, ptr, bytes + 1);
> string_unescape_any_inplace(tmp);
> synth_printf("%s", tmp);
> ptr += bytes;
> --
> 2.15.2
>

--
Samuel
---
Pour une évaluation indépendante, transparente et rigoureuse !
Je soutiens la Commission d'Évaluation de l'Inria.