[PATCH net v2] net: sungem: fix probe error cleanup

[Ruoyu Wang]

gem_init_one() calls gem_remove_one() when register_netdev() fails.
gem_remove_one() unregisters and frees resources owned by the net_device,
including the DMA block, MMIO mapping, PCI regions, and the net_device
itself. gem_init_one() then falls through to its own cleanup labels and
frees the same resources again.

Keep the register_netdev() error path in gem_init_one(): clear drvdata so
PM/remove paths do not see a half-registered device, remove the NAPI
instance added during probe, and let the existing cleanup labels release
the resources once.

The issue was found by a local static-analysis checker for probe error
paths. The reported path was manually inspected before sending this fix.

Compile-tested with CONFIG_SUNGEM=y. Runtime testing was not performed
because no sungem hardware is available.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ruoyu Wang <ruoyuw560@xxxxxxxxx>
---
v2:
- Add a Fixes tag.
- Describe how the issue was found.
- Add testing information.

v1: https://lore.kernel.org/netdev/20260620155326.80582-1-ruoyuw560@xxxxxxxxx/

 drivers/net/ethernet/sun/sungem.c | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/sun/sungem.c b/drivers/net/ethernet/sun/sungem.c
index 8e69d917d827..26974ee71352 100644
--- a/drivers/net/ethernet/sun/sungem.c
+++ b/drivers/net/ethernet/sun/sungem.c
@@ -2986,10 +2986,10 @@ static int gem_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	dev->max_mtu = GEM_MAX_MTU;
 
 	/* Register with kernel */
-	if (register_netdev(dev)) {
+	err = register_netdev(dev);
+	if (err) {
 		pr_err("Cannot register net device, aborting\n");
-		err = -ENOMEM;
-		goto err_out_free_consistent;
+		goto err_out_clear_drvdata;
 	}
 
 	/* Undo the get_cell with appropriate locking (we could use
@@ -3003,8 +3003,13 @@ static int gem_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 		    dev->dev_addr);
 	return 0;
 
+err_out_clear_drvdata:
+	pci_set_drvdata(pdev, NULL);
+	netif_napi_del(&gp->napi);
+
 err_out_free_consistent:
-	gem_remove_one(pdev);
+	dma_free_coherent(&pdev->dev, sizeof(struct gem_init_block),
+			  gp->init_block, gp->gblock_dvma);
 err_out_iounmap:
 	gem_put_cell(gp);
 	iounmap(gp->regs);
-- 
2.51.0