usb: gadget: mv_u3d: replace deprecated strncpy with strscpy

strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.

Let's opt for the new 2-argument version of strscpy() which guarantees
NUL-termination on the destination buffer and simplifies snytax. The
NUL-padding behavior that strncpy() provides is not required as u3d->eps
is already zero-allocated:
|	u3d->eps = kzalloc(size, GFP_KERNEL);

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings
Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html
Link: https://github.com/KSPP/linux/issues/90
Cc: linux-hardening@vger.kernel.org
Signed-off-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240318-strncpy-drivers-usb-gadget-udc-mv_u3d_core-c-v1-1-64f8dcdb7c07@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/gadget/udc/mv_u3d_core.c b/drivers/usb/gadget/udc/mv_u3d_core.c
index 2a421f0ff9314ba398b106a2224779d5339f6d6c..e1dd5cf25d08a0a6eb42663215d7aa00350c4eb1 100644 (file)
--- a/drivers/usb/gadget/udc/mv_u3d_core.c
+++ b/drivers/usb/gadget/udc/mv_u3d_core.c
@@ -1307,7 +1307,7 @@ static int mv_u3d_eps_init(struct mv_u3d *u3d)
        /* initialize ep0, ep0 in/out use eps[1] */
        ep = &u3d->eps[1];
        ep->u3d = u3d;
-       strncpy(ep->name, "ep0", sizeof(ep->name));
+       strscpy(ep->name, "ep0");
        ep->ep.name = ep->name;
        ep->ep.ops = &mv_u3d_ep_ops;
        ep->wedge = 0;
@@ -1337,7 +1337,7 @@ static int mv_u3d_eps_init(struct mv_u3d *u3d)
                        ep->ep.caps.dir_out = true;
                }
                ep->u3d = u3d;
-               strncpy(ep->name, name, sizeof(ep->name));
+               strscpy(ep->name, name);
                ep->ep.name = ep->name;
 
                ep->ep.caps.type_iso = true;