From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	MD Danish Anwar <danishanwar@ti.com>,
	Simon Horman <horms@kernel.org>,
	Fernando Fernandez Mancera <fmancera@suse.de>,
	Jakub Kicinski <kuba@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH 6.12 0796/1102] net: hsr: enable promiscuous mode on interlink port with fwd offload
Date: Thu, 17 Sep 2026 16:12:19 +0100
Message-ID: <20260917151600.456031180@linuxfoundation.org>
In-Reply-To: <20260917151539.408551884@linuxfoundation.org>
References: <20260917151539.408551884@linuxfoundation.org>
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6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: MD Danish Anwar <danishanwar@ti.com>

[ Upstream commit a2dc179481d18f6df7274522571b64dd50f31e81 ]

hsr_portdev_setup() skips promiscuous mode on non-master ports when
hsr->fwd_offloaded is set. fwd_offloaded is derived only from the ring
slaves' NETIF_F_HW_HSR_FWD bit, so this also skips it for the interlink
port, which never gets forwarding offload. Without promiscuous mode,
the interlink NIC drops unicast frames addressed to hsr_dev's MAC
(e.g. SAN traffic to the RedBox), breaking RedBox whenever the ring is
HW-offloaded.

Fixes: 5055cccfc2d1 ("net: hsr: Provide RedBox support (HSR-SAN)")
Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260908090856.2876114-1-danishanwar@ti.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/hsr/hsr_slave.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/net/hsr/hsr_slave.c b/net/hsr/hsr_slave.c
index ffc7259729527..e22694b727b28 100644
--- a/net/hsr/hsr_slave.c
+++ b/net/hsr/hsr_slave.c
@@ -148,9 +148,12 @@ static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
 	int res;
 
 	/* Don't use promiscuous mode for offload since L2 frame forward
-	 * happens at the offloaded hardware.
+	 * happens at the offloaded hardware. The interlink port never
+	 * gets forwarding offload (RedBox forwarding to/from it is done
+	 * by this driver), so it still needs promiscuous mode to receive
+	 * frames addressed to hsr_dev's MAC rather than its own.
 	 */
-	if (!port->hsr->fwd_offloaded) {
+	if (!port->hsr->fwd_offloaded || port->type == HSR_PT_INTERLINK) {
 		res = dev_set_promiscuity(dev, 1);
 		if (res)
 			return res;
@@ -173,7 +176,7 @@ static int hsr_portdev_setup(struct hsr_priv *hsr, struct net_device *dev,
 fail_rx_handler:
 	netdev_upper_dev_unlink(dev, hsr_dev);
 fail_upper_dev_link:
-	if (!port->hsr->fwd_offloaded)
+	if (!port->hsr->fwd_offloaded || port->type == HSR_PT_INTERLINK)
 		dev_set_promiscuity(dev, -1);
 
 	return res;
@@ -236,7 +239,7 @@ void hsr_del_port(struct hsr_port *port)
 		netdev_update_features(master->dev);
 		dev_set_mtu(master->dev, hsr_get_max_mtu(hsr));
 		netdev_rx_handler_unregister(port->dev);
-		if (!port->hsr->fwd_offloaded)
+		if (!port->hsr->fwd_offloaded || port->type == HSR_PT_INTERLINK)
 			dev_set_promiscuity(port->dev, -1);
 		if (port->type == HSR_PT_SLAVE_A || port->type == HSR_PT_SLAVE_B)
 			vlan_vids_del_by_dev(port->dev, master->dev);
-- 
2.53.0