queue-6.6/gve-prevent-ethtool-ops-after-shutdown.patch

From b4ce5a5b2972d12f3c2878f3ba26bb271a463283 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Mon, 18 Aug 2025 14:12:45 -0700
Subject: gve: prevent ethtool ops after shutdown

From: Jordan Rhee <jordanrhee@google.com>

[ Upstream commit 75a9a46d67f46d608205888f9b34e315c1786345 ]

A crash can occur if an ethtool operation is invoked
after shutdown() is called.

shutdown() is invoked during system shutdown to stop DMA operations
without performing expensive deallocations. It is discouraged to
unregister the netdev in this path, so the device may still be visible
to userspace and kernel helpers.

In gve, shutdown() tears down most internal data structures. If an
ethtool operation is dispatched after shutdown(), it will dereference
freed or NULL pointers, leading to a kernel panic. While graceful
shutdown normally quiesces userspace before invoking the reboot
syscall, forced shutdowns (as observed on GCP VMs) can still trigger
this path.

Fix by calling netif_device_detach() in shutdown().
This marks the device as detached so the ethtool ioctl handler
will skip dispatching operations to the driver.

Fixes: 974365e51861 ("gve: Implement suspend/resume/shutdown")
Signed-off-by: Jordan Rhee <jordanrhee@google.com>
Signed-off-by: Jeroen de Borst <jeroendb@google.com>
Link: https://patch.msgid.link/20250818211245.1156919-1-jeroendb@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/google/gve/gve_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/google/gve/gve_main.c b/drivers/net/ethernet/google/gve/gve_main.c
index ec189f0703f9..241a541b8edd 100644
--- a/drivers/net/ethernet/google/gve/gve_main.c
+++ b/drivers/net/ethernet/google/gve/gve_main.c
@@ -2373,6 +2373,8 @@ static void gve_shutdown(struct pci_dev *pdev)
 	struct gve_priv *priv = netdev_priv(netdev);
 	bool was_up = netif_carrier_ok(priv->dev);
 
+	netif_device_detach(netdev);
+
 	rtnl_lock();
 	if (was_up && gve_close(priv->dev)) {
 		/* If the dev was up, attempt to close, if close fails, reset */
-- 
2.50.1