[PATCH net] net: stmmac: Disable queues before netif_tx_disable in xdp_release

[PATCH net] net: stmmac: Disable queues before netif_tx_disable in xdp_release

[muhammad.nazim.amirul.nazle.asmade]

From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@altera.com>

stmmac_xdp_release() calls netif_tx_disable() before
stmmac_disable_all_queues(), which creates a race window where NAPI
is still running while TX is being disabled. If a packet is still
queued at that point, it can be processed after TX is stopped,
leading to a kernel panic.

Fix this by calling stmmac_disable_all_queues() first to stop NAPI
processing before disabling TX, matching the order already used in
stmmac_release() since 7028471edb64.

Fixes: 7028471edb64 ("net: ethernet: stmicro: stmmac: first disable all queues and disconnect in release")
Signed-off-by: Rohan G Thomas <rohan.g.thomas@altera.com>
Signed-off-by: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@altera.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 2a0d7eff88d3..75cb53938519 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -7099,15 +7099,15 @@ void stmmac_xdp_release(struct net_device *dev)
 	struct stmmac_priv *priv = netdev_priv(dev);
 	u8 chan;
 
-	/* Ensure tx function is not running */
-	netif_tx_disable(dev);
-
 	/* Disable NAPI process */
 	stmmac_disable_all_queues(priv);
 
 	for (chan = 0; chan < priv->plat->tx_queues_to_use; chan++)
 		hrtimer_cancel(&priv->dma_conf.tx_queue[chan].txtimer);
 
+	/* Ensure tx function is not running */
+	netif_tx_disable(dev);
+
 	/* Free the IRQ lines */
 	stmmac_free_irq(dev, REQ_IRQ_ERR_ALL, 0);
 
-- 
2.43.7

Re: [PATCH net] net: stmmac: Disable queues before netif_tx_disable in xdp_release

[Maxime Chevallier]

Hi,

On 7/27/26 05:06, muhammad.nazim.amirul.nazle.asmade@altera.com wrote:
> From: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@altera.com>
> 
> stmmac_xdp_release() calls netif_tx_disable() before
> stmmac_disable_all_queues(), which creates a race window where NAPI
> is still running while TX is being disabled. If a packet is still
> queued at that point, it can be processed after TX is stopped,
> leading to a kernel panic.
> 
> Fix this by calling stmmac_disable_all_queues() first to stop NAPI
> processing before disabling TX, matching the order already used in
> stmmac_release() since 7028471edb64.
> 
> Fixes: 7028471edb64 ("net: ethernet: stmicro: stmmac: first disable all queues and disconnect in release")
> Signed-off-by: Rohan G Thomas <rohan.g.thomas@altera.com>
> Signed-off-by: Nazim Amirul <muhammad.nazim.amirul.nazle.asmade@altera.com>

Reviewed-by: Maxime Chevallier <maxime.chevallier@bootlin.com>

Maxime