| From 5abcf64d9f0fc8ba5eec905954d297ec1305a869 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Fri, 15 Aug 2025 09:07:21 -0400 |
| Subject: usb: gadget: f_ncm: Fix MAC assignment NCM ethernet |
| |
| From: raub camaioni <raubcameo@gmail.com> |
| |
| [ Upstream commit 956606bafb5fc6e5968aadcda86fc0037e1d7548 ] |
| |
| This fix is already present in f_ecm.c and was never |
| propagated to f_ncm.c |
| |
| When creating multiple NCM ethernet devices |
| on a composite usb gadget device |
| each MAC address on the HOST side will be identical. |
| Having the same MAC on different network interfaces is bad. |
| |
| This fix updates the MAC address inside the |
| ncm_strings_defs global during the ncm_bind call. |
| This ensures each device has a unique MAC. |
| In f_ecm.c ecm_string_defs is updated in the same way. |
| |
| The defunct MAC assignment in ncm_alloc has been removed. |
| |
| Signed-off-by: raub camaioni <raubcameo@gmail.com> |
| Link: https://lore.kernel.org/r/20250815131358.1047525-1-raubcameo@gmail.com |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/usb/gadget/function/f_ncm.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| diff --git a/drivers/usb/gadget/function/f_ncm.c b/drivers/usb/gadget/function/f_ncm.c |
| index ca50257b95384..b1e5693373820 100644 |
| --- a/drivers/usb/gadget/function/f_ncm.c |
| +++ b/drivers/usb/gadget/function/f_ncm.c |
| @@ -1472,6 +1472,8 @@ static int ncm_bind(struct usb_configuration *c, struct usb_function *f) |
| |
| ncm_opts->bound = true; |
| |
| + ncm_string_defs[1].s = ncm->ethaddr; |
| + |
| us = usb_gstrings_attach(cdev, ncm_strings, |
| ARRAY_SIZE(ncm_string_defs)); |
| if (IS_ERR(us)) { |
| @@ -1735,7 +1737,6 @@ static struct usb_function *ncm_alloc(struct usb_function_instance *fi) |
| mutex_unlock(&opts->lock); |
| return ERR_PTR(-EINVAL); |
| } |
| - ncm_string_defs[STRING_MAC_IDX].s = ncm->ethaddr; |
| |
| spin_lock_init(&ncm->lock); |
| ncm_reset_values(ncm); |
| -- |
| 2.51.0 |
| |
