`strncpy` is deprecated for use on NUL-terminated destination strings [1].
We should prefer more robust and less ambiguous string interfaces.
A suitable replacement is `strscpy` [2] due to the fact that it guarantees
NUL-termination on the destination buffer. With this, we can also drop
the now unnecessary `CPUIDLE_(NAME|DESC)_LEN - 1` pieces.
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
---
drivers/cpuidle/dt_idle_states.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/cpuidle/dt_idle_states.c b/drivers/cpuidle/dt_idle_states.c
index 12fec92a85fd..97feb7d8fb23 100644
--- a/drivers/cpuidle/dt_idle_states.c
+++ b/drivers/cpuidle/dt_idle_states.c
@@ -84,8 +84,8 @@ static int init_state_node(struct cpuidle_state *idle_state,
* replace with kstrdup and pointer assignment when name
* and desc become string pointers
*/
- strncpy(idle_state->name, state_node->name, CPUIDLE_NAME_LEN - 1);
- strncpy(idle_state->desc, desc, CPUIDLE_DESC_LEN - 1);
+ strscpy(idle_state->name, state_node->name, CPUIDLE_NAME_LEN);
+ strscpy(idle_state->desc, desc, CPUIDLE_DESC_LEN);
return 0;
}
---
base-commit: 2dde18cd1d8fac735875f2e4987f11817cc0bc2c
change-id: 20230913-strncpy-drivers-cpuidle-dt_idle_states-c-c84ea03c1379
Best regards,
--
Justin Stitt <[email protected]>
On Wed, Sep 13, 2023 at 12:23:19AM +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
>
> We should prefer more robust and less ambiguous string interfaces.
>
> A suitable replacement is `strscpy` [2] due to the fact that it guarantees
> NUL-termination on the destination buffer. With this, we can also drop
> the now unnecessary `CPUIDLE_(NAME|DESC)_LEN - 1` pieces.
>
> 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]>
A very regular strncpy/strscpy conversion. :)
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook
On Wed, 13 Sep 2023 00:23:19 +0000, Justin Stitt wrote:
> `strncpy` is deprecated for use on NUL-terminated destination strings [1].
>
> We should prefer more robust and less ambiguous string interfaces.
>
> A suitable replacement is `strscpy` [2] due to the fact that it guarantees
> NUL-termination on the destination buffer. With this, we can also drop
> the now unnecessary `CPUIDLE_(NAME|DESC)_LEN - 1` pieces.
>
> [...]
Applied to for-next/hardening, thanks!
[1/1] cpuidle: dt: refactor deprecated strncpy
https://git.kernel.org/kees/c/fd94c38f8441
Take care,
--
Kees Cook