[PATCH net v3 01/10] net: stmmac: unwind the WoL IRQ after a safety IRQ request failure

[James Hilliard]

The IRQ setup paths request the MAC IRQ, then the optional WoL IRQ, then
the common safety IRQ. If requesting the safety IRQ fails, cleanup must
release the WoL and MAC IRQs, but not the failed safety IRQ.

The REQ_IRQ_ERR_SFTY case instead frees the safety IRQ and skips the WoL
IRQ. Allocation fault injection during live XDP reopening reproduces a
"Trying to free already-free IRQ" warning and leaves the WoL handler
registered after the datapath resources have been released. A subsequent
open can then fail to request that still-owned IRQ.

Move safety IRQ cleanup before REQ_IRQ_ERR_SFTY and WoL IRQ cleanup after
it. This restores reverse acquisition order for both shared and MSI IRQ
setup, including unwind after failures in later per-queue IRQ requests.

Fixes: 5c2215167d12 ("net: stmmac: Add driver support for common safety IRQ")
Signed-off-by: James Hilliard <james.hilliard1@xxxxxxxxx>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 3f34d491c959..4f3d452c3503 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -3797,13 +3797,13 @@ static void stmmac_free_irq(struct net_device *dev,
 			free_irq(msi->sfty_ce_irq, dev);
 		fallthrough;
 	case REQ_IRQ_ERR_SFTY_CE:
-		if (priv->wol_irq > 0 && priv->wol_irq != dev->irq)
-			free_irq(priv->wol_irq, dev);
-		fallthrough;
-	case REQ_IRQ_ERR_SFTY:
 		if (priv->sfty_irq > 0 && priv->sfty_irq != dev->irq)
 			free_irq(priv->sfty_irq, dev);
 		fallthrough;
+	case REQ_IRQ_ERR_SFTY:
+		if (priv->wol_irq > 0 && priv->wol_irq != dev->irq)
+			free_irq(priv->wol_irq, dev);
+		fallthrough;
 	case REQ_IRQ_ERR_WOL:
 		free_irq(dev->irq, dev);
 		fallthrough;

-- 
2.53.0