[PATCH net] r8169: fix incorrect mac address assignment

The original changes brakes MAC address assignment on older chip
versions (see bug report [0]), and it brakes random MAC assignment.

is_valid_ether_addr() requires that its argument is word-aligned.
Add the missing alignment to array mac_addr.

[0] https://bugzilla.kernel.org/show_bug.cgi?id=215087

Fixes: 1c5d09d58748 ("ethernet: r8169: use eth_hw_addr_set()")
Reported-by: Richard Herbert <redacted>
Tested-by: Richard Herbert <redacted>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
---
Missing alignment and initialization of MAC address variable may affect
also other drivers where a similar change was made.
---
 drivers/net/ethernet/realtek/r8169_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index e896e5eca..e9b560051 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c

@@ -5226,8 +5226,8 @@ static int rtl_get_ether_clk(struct rtl8169_private *tp)
 
 static void rtl_init_mac_address(struct rtl8169_private *tp)
 {
+	u8 mac_addr[ETH_ALEN] __aligned(2) = {};
 	struct net_device *dev = tp->dev;
-	u8 mac_addr[ETH_ALEN];
 	int rc;
 
 	rc = eth_platform_get_mac_address(tp_to_dev(tp), mac_addr);

@@ -5242,7 +5242,8 @@ static void rtl_init_mac_address(struct rtl8169_private *tp)
 	if (is_valid_ether_addr(mac_addr))
 		goto done;
 
-	eth_hw_addr_random(dev);
+	eth_random_addr(mac_addr);
+	dev->addr_assign_type = NET_ADDR_RANDOM;
 	dev_warn(tp_to_dev(tp), "can't read MAC address, setting random one\n");
 done:
 	eth_hw_addr_set(dev, mac_addr);

-- 
2.34.0

On Mon, 22 Nov 2021 22:35:33 +0100 Heiner Kallweit wrote:

The original changes brakes MAC address assignment on older chip
versions (see bug report [0]), and it brakes random MAC assignment.

is_valid_ether_addr() requires that its argument is word-aligned.
Add the missing alignment to array mac_addr.

[0] https://bugzilla.kernel.org/show_bug.cgi?id=215087

Fixes: 1c5d09d58748 ("ethernet: r8169: use eth_hw_addr_set()")
Reported-by: Richard Herbert <redacted>
Tested-by: Richard Herbert <redacted>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>

Acked-by: Jakub Kicinski <kuba@kernel.org>

Thanks!

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller [off-list ref]:

On Mon, 22 Nov 2021 22:35:33 +0100 you wrote:

The original changes brakes MAC address assignment on older chip
versions (see bug report [0]), and it brakes random MAC assignment.

is_valid_ether_addr() requires that its argument is word-aligned.
Add the missing alignment to array mac_addr.

[0] https://bugzilla.kernel.org/show_bug.cgi?id=215087

[...]

Here is the summary with links:
  - [net] r8169: fix incorrect mac address assignment
    https://git.kernel.org/netdev/net/c/c75a9ad43691

You are awesome, thank you!
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