[PATCH] accel/habanalabs: refactor deprecated strncpy

[PATCH] accel/habanalabs: refactor deprecated strncpy

[Justin Stitt]

`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`!

There is likely no bug happening in this case since HL_STR_MAX is
strictly larger than all source strings. Nonetheless, prefer a safer and
more robust interface.

It should also be noted that `strscpy` will not pad like `strncpy`. If
this NUL-padding behavior is _required_ we should use `strscpy_pad`
instead of `strscpy`.

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@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
---
Note: build-tested only.
---
 drivers/accel/habanalabs/common/habanalabs_drv.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/accel/habanalabs/common/habanalabs_drv.c b/drivers/accel/habanalabs/common/habanalabs_drv.c
index 7263e84c1a4d..d9a3418b5ae4 100644
--- a/drivers/accel/habanalabs/common/habanalabs_drv.c
+++ b/drivers/accel/habanalabs/common/habanalabs_drv.c
@@ -408,13 +408,13 @@ static int create_hdev(struct hl_device **dev, struct pci_dev *pdev)
 	hdev->pdev = pdev;
 
 	/* Assign status description string */
-	strncpy(hdev->status[HL_DEVICE_STATUS_OPERATIONAL], "operational", HL_STR_MAX);
-	strncpy(hdev->status[HL_DEVICE_STATUS_IN_RESET], "in reset", HL_STR_MAX);
-	strncpy(hdev->status[HL_DEVICE_STATUS_MALFUNCTION], "disabled", HL_STR_MAX);
-	strncpy(hdev->status[HL_DEVICE_STATUS_NEEDS_RESET], "needs reset", HL_STR_MAX);
-	strncpy(hdev->status[HL_DEVICE_STATUS_IN_DEVICE_CREATION],
-					"in device creation", HL_STR_MAX);
-	strncpy(hdev->status[HL_DEVICE_STATUS_IN_RESET_AFTER_DEVICE_RELEASE],
+	strscpy(hdev->status[HL_DEVICE_STATUS_OPERATIONAL], "operational", HL_STR_MAX);
+	strscpy(hdev->status[HL_DEVICE_STATUS_IN_RESET], "in reset", HL_STR_MAX);
+	strscpy(hdev->status[HL_DEVICE_STATUS_MALFUNCTION], "disabled", HL_STR_MAX);
+	strscpy(hdev->status[HL_DEVICE_STATUS_NEEDS_RESET], "needs reset", HL_STR_MAX);
+	strscpy(hdev->status[HL_DEVICE_STATUS_IN_DEVICE_CREATION],
+		  		"in device creation", HL_STR_MAX);
+	strscpy(hdev->status[HL_DEVICE_STATUS_IN_RESET_AFTER_DEVICE_RELEASE],
 					"in reset after device release", HL_STR_MAX);
 
 

---
base-commit: 706a741595047797872e669b3101429ab8d378ef
change-id: 20230823-strncpy-drivers-accel-habanalabs-common-habanalabs_drv-7ffecf6882ed

Best regards,
--
Justin Stitt <justinstitt@google.com>

Re: [PATCH] accel/habanalabs: refactor deprecated strncpy

[Stanislaw Gruszka]

On Wed, Aug 23, 2023 at 12:23:08AM +0000, Justin Stitt wrote:
> `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`!
> 
> There is likely no bug happening in this case since HL_STR_MAX is
> strictly larger than all source strings. Nonetheless, prefer a safer and
> more robust interface.
> 
> It should also be noted that `strscpy` will not pad like `strncpy`. If
> this NUL-padding behavior is _required_ we should use `strscpy_pad`
> instead of `strscpy`.
> 
> 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@vger.kernel.org
> Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>

Re: [PATCH] accel/habanalabs: refactor deprecated strncpy

[Oded Gabbay]

On Fri, Aug 25, 2023 at 12:19 PM Stanislaw Gruszka
<stanislaw.gruszka@linux.intel.com> wrote:
>
> On Wed, Aug 23, 2023 at 12:23:08AM +0000, Justin Stitt wrote:
> > `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`!
> >
> > There is likely no bug happening in this case since HL_STR_MAX is
> > strictly larger than all source strings. Nonetheless, prefer a safer and
> > more robust interface.
> >
> > It should also be noted that `strscpy` will not pad like `strncpy`. If
> > this NUL-padding behavior is _required_ we should use `strscpy_pad`
> > instead of `strscpy`.
> >
> > 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@vger.kernel.org
> > Signed-off-by: Justin Stitt <justinstitt@google.com>
> Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
>
Applied to -next
Thanks,
Oded