6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Breno Leitao commit 16f3a28cf5f876a7f3550d8f4c870a7b41bcfaef upstream. Move the freeing of the dummy net_device from mtk_free_dev() to mtk_remove(). Previously, if alloc_netdev_dummy() failed in mtk_probe(), eth->dummy_dev would be NULL. The error path would then call mtk_free_dev(), which in turn called free_netdev() assuming dummy_dev was allocated (but it was not), potentially causing a NULL pointer dereference. By moving free_netdev() to mtk_remove(), we ensure it's only called when mtk_probe() has succeeded and dummy_dev is fully allocated. This addresses a potential NULL pointer dereference detected by Smatch[1]. Fixes: b209bd6d0bff ("net: mediatek: mtk_eth_sock: allocate dummy net_device dynamically") Reported-by: Dan Carpenter Closes: https://lore.kernel.org/all/4160f4e0-cbef-4a22-8b5d-42c4d399e1f7@stanley.mountain/ [1] Suggested-by: Dan Carpenter Reviewed-by: Dan Carpenter Signed-off-by: Breno Leitao Reviewed-by: Simon Horman Link: https://patch.msgid.link/20240724080524.2734499-1-leitao@debian.org Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mediatek/mtk_eth_soc.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/drivers/net/ethernet/mediatek/mtk_eth_soc.c +++ b/drivers/net/ethernet/mediatek/mtk_eth_soc.c @@ -4249,8 +4249,6 @@ static int mtk_free_dev(struct mtk_eth * dst_release(ð->dsa_meta[i]->dst); } - free_netdev(eth->dummy_dev); - return 0; } @@ -5103,6 +5101,7 @@ static int mtk_remove(struct platform_de netif_napi_del(ð->tx_napi); netif_napi_del(ð->rx_napi); mtk_cleanup(eth); + free_netdev(eth->dummy_dev); mtk_mdio_cleanup(eth); return 0;