netdev - [PATCH net-next] net: add check for current MAC address in dev_set_mac

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20230609165241.827338-1-piotrx.gardocki@intel.com>
Date: Fri,  9 Jun 2023 18:52:41 +0200
From: Piotr Gardocki <piotrx.gardocki@...el.com>
To: netdev@...r.kernel.org
Cc: piotrx.gardocki@...el.com,
	przemyslaw.kitszel@...el.com,
	michal.swiatkowski@...ux.intel.com,
	pmenzel@...gen.mpg.de,
	kuba@...nel.org,
	maciej.fijalkowski@...el.com,
	anthony.l.nguyen@...el.com,
	simon.horman@...igine.com,
	aleksander.lobakin@...el.com
Subject: [PATCH net-next] net: add check for current MAC address in dev_set_mac_address

In some cases it is possible for kernel to come with request
to change primary MAC address to the address that is already
set on the given interface.

This patch adds proper check to return fast from the function
in these cases.

An example of such case is adding an interface to bonding
channel in balance-alb mode:
modprobe bonding mode=balance-alb miimon=100 max_bonds=1
ip link set bond0 up
ifenslave bond0 <eth>

Signed-off-by: Piotr Gardocki <piotrx.gardocki@...el.com>
---
 net/core/dev.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/core/dev.c b/net/core/dev.c
index 99d99b247bc9..c2c3ec61397b 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -8820,6 +8820,8 @@ int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
 		return -EINVAL;
 	if (!netif_device_present(dev))
 		return -ENODEV;
+	if (ether_addr_equal(dev->dev_addr, sa->sa_data))
+		return 0;
 	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
 	if (err)
 		return err;
-- 
2.34.1