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 [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.
Found with: $ rg "strncpy\("
---
drivers/usb/gadget/udc/mv_u3d_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/gadget/udc/mv_u3d_core.c b/drivers/usb/gadget/udc/mv_u3d_core.c
index 2a421f0ff931..e1dd5cf25d08 100644
--- 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;
---
base-commit: bf3a69c6861ff4dc7892d895c87074af7bc1c400
change-id: 20240318-strncpy-drivers-usb-gadget-udc-mv_u3d_core-c-50ea7422311c
Best regards,
--
Justin Stitt <[email protected]>
On Mon, Mar 18, 2024 at 11:31:53PM +0000, Justin Stitt wrote:
> 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 [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]>
Thanks!
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook