[PATCH 6.18 672/752] net: cpsw_new: Fix potential unregister of netdev that has not been registered yet

Sasha Levin
2026-02-28T17:58:06Z

From: Kevin Hao <haokexin@gmail.com>

[ Upstream commit 9d724b34fbe13b71865ad0906a4be97571f19cf5 ]

If an error occurs during register_netdev() for the first MAC in
cpsw_register_ports(), even though cpsw->slaves[0].ndev is set to NULL,
cpsw->slaves[1].ndev would remain unchanged. This could later cause
cpsw_unregister_ports() to attempt unregistering the second MAC.
To address this, add a check for ndev->reg_state before calling
unregister_netdev(). With this change, setting cpsw->slaves[i].ndev
to NULL becomes unnecessary and can be removed accordingly.

Fixes: ed3525eda4c4 ("net: ethernet: ti: introduce cpsw switchdev based driver part 1 - dual-emac")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Cc: stable@vger.kernel.org
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Link: https://patch.msgid.link/20260205-cpsw-error-path-v1-2-6e58bae6b299@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/ti/cpsw_new.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ti/cpsw_new.c b/drivers/net/ethernet/ti/cpsw_new.c
index 4d763e571cfa9..fd3931d667021 100644
--- a/drivers/net/ethernet/ti/cpsw_new.c
+++ b/drivers/net/ethernet/ti/cpsw_new.c
@@ -1472,7 +1472,7 @@ static void cpsw_unregister_ports(struct cpsw_common *cpsw)

for (i = 0; i < cpsw->data.slaves; i++) {
ndev = cpsw->slaves[i].ndev;
- if (!ndev)
+ if (!ndev || ndev->reg_state != NETREG_REGISTERED)
continue;

priv = netdev_priv(ndev);
@@ -1494,7 +1494,6 @@ static int cpsw_register_ports(struct cpsw_common *cpsw)
if (ret) {
dev_err(cpsw->dev,
"cpsw: err registering net device%d\n", i);
- cpsw->slaves[i].ndev = NULL;
break;
}
}
--
2.51.0