5.4-stable review patch. If anyone has any objections, please let me know.
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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);