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From: "Rénich Bon Ćirić" <renich@evalinux.com>
To: netdev@vger.kernel.org
Cc: "Joshua Washington" <joshwash@google.com>,
	"Harshitha Ramamurthy" <hramamurthy@google.com>,
	"Jakub Kicinski" <kuba@kernel.org>,
	"Eric Dumazet" <edumazet@google.com>,
	"Paolo Abeni" <pabeni@redhat.com>,
	"David S . Miller" <davem@davemloft.net>,
	"Andrew Lunn" <andrew+netdev@lunn.ch>,
	"Rénich Bon Ćirić" <renich@evalinux.com>,
	"Przemek Kitszel" <przemyslaw.kitszel@intel.com>
Subject: [PATCH net v2] gve: use gve_schedule_reset() on AdminQ flow rule timeout
Date: Fri,  7 Aug 2026 18:21:36 -0600	[thread overview]
Message-ID: <20260808002136.2064827-1-renich@evalinux.com> (raw)

When an AdminQ command to configure a flow rule times out in
gve_adminq_configure_flow_rule(), the driver currently calls
gve_reset(priv, true) synchronously.

When flow rule configuration is invoked under netlink or ethtool
callbacks, gve_reset() attempts to acquire rtnl_lock while already
executing within an inner driver lock context. This violates the driver's
lock hierarchy and causes an AB-BA circular lock inversion deadlock.

Resolve this lock inversion by replacing synchronous gve_reset() with
gve_schedule_reset(). This defers reset execution safely to
gve_service_task out-of-band under the proper lock ordering.

Co-developed with Gemini AI (Google DeepMind) for root cause analysis
and patch formulation.

Fixes: 57718b60df9b ("gve: Add flow steering adminq commands")
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Rénich Bon Ćirić <renich@evalinux.com>
---
v2: https://lore.kernel.org/netdev/20260806085112.385934-1-renich@woralelandia.com/
  - Update Fixes tag to 57718b60df9b per Przemek Kitszel review.
  - Add Reviewed-by tag from Przemek Kitszel.
  - Remove misleading GitHub Issue #93 link (opened for CentOS Stream 10 NAPI bug).
  - Add explicit AI co-development disclosure in commit body.
v1: https://lore.kernel.org/netdev/20260806085112.385934-1-renich@woralelandia.com/

 drivers/net/ethernet/google/gve/gve_adminq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/google/gve/gve_adminq.c b/drivers/net/ethernet/google/gve/gve_adminq.c
index 08587bf12345..2037b1767890 100644
--- a/drivers/net/ethernet/google/gve/gve_adminq.c
+++ b/drivers/net/ethernet/google/gve/gve_adminq.c
@@ -1322,7 +1322,7 @@ gve_adminq_configure_flow_rule(struct gve_priv *priv,
 
 	if (err == -ETIME) {
 		dev_err(&priv->pdev->dev, "Timeout to configure the flow rule, trigger reset");
-		gve_reset(priv, true);
+		gve_schedule_reset(priv);
 	} else if (!err) {
 		priv->flow_rules_cache.rules_cache_synced = false;
 	}
-- 
2.45.2

                 reply	other threads:[~2026-08-08  0:21 UTC|newest]

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