[PATCH] x86/hpet: refactor deprecated strncpy

From: Justin Stitt
Date: Tue Aug 22 2023 - 18:13:47 EST


`strncpy` is deprecated for use on NUL-terminated destination strings [1].

A suitable replacement is `strscpy` [2] due to the fact that it
guarantees NUL-termination on its destination buffer argument which is
_not_ the case for `strncpy`!

In this case, it is a simple swap from `strncpy` to `strscpy`. There is
one slight difference, though. If NUL-padding is a functional
requirement here we should opt for `strscpy_pad`. It seems like this
shouldn't be needed as I see no obvious signs of any padding being
required.

Link: 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: linux-hardening@xxxxxxxxxxxxxxx
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
Note: build-tested only.
---
arch/x86/kernel/hpet.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index c8eb1ac5125a..1648aa0204d9 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -421,7 +421,7 @@ static void __init hpet_legacy_clockevent_register(struct hpet_channel *hc)
* the IO_APIC has been initialized.
*/
hc->cpu = boot_cpu_data.cpu_index;
- strncpy(hc->name, "hpet", sizeof(hc->name));
+ strscpy(hc->name, "hpet", sizeof(hc->name));
hpet_init_clockevent(hc, 50);

hc->evt.tick_resume = hpet_clkevt_legacy_resume;

---
base-commit: 706a741595047797872e669b3101429ab8d378ef
change-id: 20230822-strncpy-arch-x86-kernel-hpet-4d57cbd8eb96

Best regards,
--
Justin Stitt <justinstitt@xxxxxxxxxx>