Re: [PATCH net] gve: use gve_schedule_reset() on AdminQ flow rule timeout
From: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Date: 2026-08-06 09:31:49
On 8/6/26 10:51, Rénich Bon Ćirić wrote:
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.
Fixes: 8ffade77b633 ("gve: Flow steering trigger reset only for timeout error")
this is not the commit that introduced the bug
initial implementation was in commit 57718b60df9b ("gve: Add flow
steering adminq commands"), so this could be used as "wrong code intro",
but likely it was the addition of netdev_lock() around ethtool call,
that exposed the issue, and should be the actual Fixes tag
quoted hunk ↗ jump to hunk
Link: https://github.com/GoogleCloudPlatform/compute-virtual-ethernet-linux/issues/93 Signed-off-by: Rénich Bon Ćirić <redacted> --- 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; }
code looks good, after updating Fixes tag, feel free to add my: Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>