From: Rosen Penev <rosenp@gmail.com>
To: netdev@vger.kernel.org
Cc: Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Rosen Penev <rosenp@gmail.com>,
linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] net: emac: mal: replace devm_request_irq with request_irq to fix probe error race
Date: Thu, 2 Jul 2026 16:50:36 -0700 [thread overview]
Message-ID: <20260702235036.1325731-1-rosenp@gmail.com> (raw)
devm_request_irq() is a managed resource: the IRQ is not freed until
devres_release_all() runs after the probe function returns. In the
probe error path, free_netdev(mal->dummy_dev) and dcr_unmap() execute
while the IRQ is still live. If the shared IRQ fires during cleanup,
the handler accesses unmapped DCR registers (crash) or the already-
freed dummy_dev (use-after-free).
Switch to plain request_irq() with per-IRQ error labels that tear down
only the IRQs that were successfully registered, and add the matching
free_irq() calls in mal_remove().
Fixes: 14f59154ff0b ("net: ibm: emac: mal: use devm for request_irq")
Assisted-by: opencode:big-pickle
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
drivers/net/ethernet/ibm/emac/mal.c | 43 +++++++++++++++++++----------
1 file changed, 29 insertions(+), 14 deletions(-)
diff --git a/drivers/net/ethernet/ibm/emac/mal.c b/drivers/net/ethernet/ibm/emac/mal.c
index eab7a487bf08..5c3bf05ca6a5 100644
--- a/drivers/net/ethernet/ibm/emac/mal.c
+++ b/drivers/net/ethernet/ibm/emac/mal.c
@@ -656,26 +656,26 @@ static int mal_probe(struct platform_device *ofdev)
hdlr_rxde = mal_rxde;
}
- err = devm_request_irq(&ofdev->dev, mal->serr_irq, hdlr_serr, irqflags,
- "MAL SERR", mal);
+ err = request_irq(mal->serr_irq, hdlr_serr, irqflags,
+ "MAL SERR", mal);
if (err)
goto fail_dummy;
- err = devm_request_irq(&ofdev->dev, mal->txde_irq, hdlr_txde, irqflags,
- "MAL TX DE", mal);
+ err = request_irq(mal->txde_irq, hdlr_txde, irqflags,
+ "MAL TX DE", mal);
if (err)
- goto fail_dummy;
- err = devm_request_irq(&ofdev->dev, mal->txeob_irq, mal_txeob, 0,
- "MAL TX EOB", mal);
+ goto fail_serr_irq;
+ err = request_irq(mal->txeob_irq, mal_txeob, 0,
+ "MAL TX EOB", mal);
if (err)
- goto fail_dummy;
- err = devm_request_irq(&ofdev->dev, mal->rxde_irq, hdlr_rxde, irqflags,
- "MAL RX DE", mal);
+ goto fail_txde_irq;
+ err = request_irq(mal->rxde_irq, hdlr_rxde, irqflags,
+ "MAL RX DE", mal);
if (err)
- goto fail_dummy;
- err = devm_request_irq(&ofdev->dev, mal->rxeob_irq, mal_rxeob, 0,
- "MAL RX EOB", mal);
+ goto fail_txeob_irq;
+ err = request_irq(mal->rxeob_irq, mal_rxeob, 0,
+ "MAL RX EOB", mal);
if (err)
- goto fail_dummy;
+ goto fail_rxde_irq;
/* Enable all MAL SERR interrupt sources */
set_mal_dcrn(mal, MAL_IER, MAL_IER_EVENTS);
@@ -694,6 +694,14 @@ static int mal_probe(struct platform_device *ofdev)
return 0;
+ fail_rxde_irq:
+ free_irq(mal->rxde_irq, mal);
+ fail_txeob_irq:
+ free_irq(mal->txeob_irq, mal);
+ fail_txde_irq:
+ free_irq(mal->txde_irq, mal);
+ fail_serr_irq:
+ free_irq(mal->serr_irq, mal);
fail_dummy:
free_netdev(mal->dummy_dev);
fail_unmap:
@@ -718,6 +726,13 @@ static void mal_remove(struct platform_device *ofdev)
mal_reset(mal);
+ /* Free IRQs before freeing resources they access */
+ free_irq(mal->serr_irq, mal);
+ free_irq(mal->txde_irq, mal);
+ free_irq(mal->txeob_irq, mal);
+ free_irq(mal->rxde_irq, mal);
+ free_irq(mal->rxeob_irq, mal);
+
free_netdev(mal->dummy_dev);
dcr_unmap(mal->dcr_host, 0x100);
--
2.55.0
reply other threads:[~2026-07-02 23:50 UTC|newest]
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