[PATCH] firmware: ti_sci: refactor deprecated strncpy

From: Justin Stitt
Date: Wed Sep 13 2023 - 16:23:07 EST


`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.

It does not seem like `ver->firmware_description` requires NUL-padding
(which is a behavior that strncpy provides) but if it does 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: linux-hardening@xxxxxxxxxxxxxxx
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
Note: build-tested only.
---
drivers/firmware/ti_sci.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 26a37f47f4ca..ce546f391959 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -485,7 +485,7 @@ static int ti_sci_cmd_get_revision(struct ti_sci_info *info)
ver->abi_major = rev_info->abi_major;
ver->abi_minor = rev_info->abi_minor;
ver->firmware_revision = rev_info->firmware_revision;
- strncpy(ver->firmware_description, rev_info->firmware_description,
+ strscpy(ver->firmware_description, rev_info->firmware_description,
sizeof(ver->firmware_description));

fail:

---
base-commit: 3669558bdf354cd352be955ef2764cde6a9bf5ec
change-id: 20230913-strncpy-drivers-firmware-ti_sci-c-22667413c18f

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