This is a note to let you know that I've just added the patch titled
usb: gadget: u_ether: fix race in setting MAC address in setup phase
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
usb-gadget-u_ether-fix-race-in-setting-mac-address-in-setup-phase.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 890d5b40908bfd1a79be018d2d297cf9df60f4ee Mon Sep 17 00:00:00 2001
From: Marian Postevca <posteuca@xxxxxxxxx>
Date: Sat, 4 Dec 2021 23:49:12 +0200
Subject: usb: gadget: u_ether: fix race in setting MAC address in setup phase
From: Marian Postevca <posteuca@xxxxxxxxx>
commit 890d5b40908bfd1a79be018d2d297cf9df60f4ee upstream.
When listening for notifications through netlink of a new interface being
registered, sporadically, it is possible for the MAC to be read as zero.
The zero MAC address lasts a short period of time and then switches to a
valid random MAC address.
This causes problems for netd in Android, which assumes that the interface
is malfunctioning and will not use it.
In the good case we get this log:
InterfaceController::getCfg() ifName usb0
hwAddr 92:a8:f0:73:79:5b ipv4Addr 0.0.0.0 flags 0x1002
In the error case we get these logs:
InterfaceController::getCfg() ifName usb0
hwAddr 00:00:00:00:00:00 ipv4Addr 0.0.0.0 flags 0x1002
netd : interfaceGetCfg("usb0")
netd : interfaceSetCfg() -> ServiceSpecificException
(99, "[Cannot assign requested address] : ioctl() failed")
The reason for the issue is the order in which the interface is setup,
it is first registered through register_netdev() and after the MAC
address is set.
Fixed by first setting the MAC address of the net_device and after that
calling register_netdev().
Fixes: bcd4a1c40bee885e ("usb: gadget: u_ether: construct with default values and add setters/getters")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Marian Postevca <posteuca@xxxxxxxxx>
Link: https://lore.kernel.org/r/20211204214912.17627-1-posteuca@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/u_ether.c | 16 ++++++----------
1 file changed, 6 insertions(+), 10 deletions(-)
--- 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/etherdevice.h>
#include "u_ether.h"
@@ -861,19 +862,23 @@ int gether_register_netdev(struct net_de
{
struct eth_dev *dev;
struct usb_gadget *g;
- struct sockaddr sa;
int status;
if (!net->dev.parent)
return -EINVAL;
dev = netdev_priv(net);
g = dev->gadget;
+
+ net->addr_assign_type = NET_ADDR_RANDOM;
+ eth_hw_addr_set(net, dev->dev_mac);
+
status = register_netdev(net);
if (status < 0) {
dev_dbg(&g->dev, "register_netdev failed, %d\n", status);
return status;
} else {
INFO(dev, "HOST MAC %pM\n", dev->host_mac);
+ INFO(dev, "MAC %pM\n", dev->dev_mac);
/* two kinds of host-initiated state changes:
* - iff DATA transfer is active, carrier is "on"
@@ -881,15 +886,6 @@ int gether_register_netdev(struct net_de
*/
netif_carrier_off(net);
}
- sa.sa_family = net->type;
- memcpy(sa.sa_data, dev->dev_mac, ETH_ALEN);
- rtnl_lock();
- status = dev_set_mac_address(net, &sa, NULL);
- rtnl_unlock();
- if (status)
- pr_warn("cannot set self ethernet address: %d\n", status);
- else
- INFO(dev, "MAC %pM\n", dev->dev_mac);
return status;
}
Patches currently in stable-queue which might be from posteuca@xxxxxxxxx are
queue-5.15/usb-gadget-u_ether-fix-race-in-setting-mac-address-in-setup-phase.patch
