The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 3c0f4f09c063e143822393d99cb2b19a85451c07 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2023052211-lying-sandworm-11db@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
3c0f4f09c063 ("usb: gadget: u_ether: Fix host MAC address case") 938fc6453176 ("usb: gadget: u_ether: Convert prints to device prints") 508aeb54e4f0 ("usb: gadget: u_ether: Remove duplicated include in u_ether.c") 890d5b40908b ("usb: gadget: u_ether: fix race in setting MAC address in setup phase")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 3c0f4f09c063e143822393d99cb2b19a85451c07 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Konrad=20Gr=C3=A4fe?= k.graefe@gateware.de Date: Fri, 5 May 2023 16:36:40 +0200 Subject: [PATCH] usb: gadget: u_ether: Fix host MAC address case MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit
The CDC-ECM specification [1] requires to send the host MAC address as an uppercase hexadecimal string in chapter "5.4 Ethernet Networking Functional Descriptor": The Unicode character is chosen from the set of values 30h through 39h and 41h through 46h (0-9 and A-F).
However, snprintf(.., "%pm", ..) generates a lowercase MAC address string. While most host drivers are tolerant to this, UsbNcm.sys on Windows 10 is not. Instead it uses a different MAC address with all bytes set to zero including and after the first byte containing a lowercase letter. On Windows 11 Microsoft fixed it, but apparently they did not backport the fix.
This change fixes the issue by upper-casing the MAC to comply with the specification.
[1]: https://www.usb.org/document-library/class-definitions-communication-devices..., file ECM120.pdf
Fixes: bcd4a1c40bee ("usb: gadget: u_ether: construct with default values and add setters/getters") Cc: stable@vger.kernel.org Signed-off-by: Konrad Gräfe k.graefe@gateware.de Link: https://lore.kernel.org/r/20230505143640.443014-1-k.graefe@gateware.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c index 6956ad8ba8dd..a366abb45623 100644 --- a/drivers/usb/gadget/function/u_ether.c +++ b/drivers/usb/gadget/function/u_ether.c @@ -17,6 +17,7 @@ #include <linux/etherdevice.h> #include <linux/ethtool.h> #include <linux/if_vlan.h> +#include <linux/string_helpers.h> #include <linux/usb/composite.h>
#include "u_ether.h" @@ -965,6 +966,8 @@ int gether_get_host_addr_cdc(struct net_device *net, char *host_addr, int len) dev = netdev_priv(net); snprintf(host_addr, len, "%pm", dev->host_mac);
+ string_upper(host_addr, host_addr); + return strlen(host_addr); } EXPORT_SYMBOL_GPL(gether_get_host_addr_cdc);