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From: Manish Baing <manishbaing2789@gmail.com>
To: perex@perex.cz, tiwai@suse.com, nicolas.ferre@microchip.com,
	alexandre.belloni@bootlin.com, claudiu.beznea@tuxon.dev
Cc: linux-sound@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, manishbaing2789@gmail.com,
	Sashiko AI <sashiko-bot@kernel.org>
Subject: [PATCH 2/2] ASoC: atmel: ac97c: Fix use-after-free on driver teardown
Date: Sat, 15 Aug 2026 16:27:06 +0000	[thread overview]
Message-ID: <20260815162707.353893-3-manishbaing2789@gmail.com> (raw)
In-Reply-To: <20260815162707.353893-1-manishbaing2789@gmail.com>

In atmel_ac97c_remove() and the probe error path, the driver disables
clocks and unmaps memory before freeing the IRQ. If a stray interrupt
fires during this window, the handler will attempt to access unmapped
memory or unclocked hardware, resulting in a kernel panic.

Reorder the teardown sequence to call free_irq() first, adhering to
the standard reverse-initialization order.

Running make W=1 returns no errors. I was unable to test the patch
because I do not have the hardware. The issue was flagged by the
Sashiko AI bot.

Link: https://sashiko.dev/#/patchset/20260530052812.115994-1-manishbaing2789@gmail.com?part=1
Reported-by: Sashiko AI <sashiko-bot@kernel.org>

Signed-off-by: Manish Baing <manishbaing2789@gmail.com>
---
 sound/atmel/ac97c.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/sound/atmel/ac97c.c b/sound/atmel/ac97c.c
index 205475157e72..24a27e67f15f 100644
--- a/sound/atmel/ac97c.c
+++ b/sound/atmel/ac97c.c
@@ -789,7 +789,7 @@ static int atmel_ac97c_probe(struct platform_device *pdev)
 	retval = snd_card_register(card);
 	if (retval) {
 		dev_dbg(&pdev->dev, "could not register sound card\n");
-		goto err_ac97_bus;
+		goto err_snd_card_register;
 	}
 
 	platform_set_drvdata(pdev, card);
@@ -799,11 +799,12 @@ static int atmel_ac97c_probe(struct platform_device *pdev)
 
 	return 0;
 
+err_snd_card_register:
+	free_irq(irq, chip);
 err_ac97_bus:
+err_request_irq:
 	iounmap(chip->regs);
 err_ioremap:
-	free_irq(irq, chip);
-err_request_irq:
 	snd_card_free(card);
 err_snd_card_new:
 	clk_disable_unprepare(pclk);
@@ -841,10 +842,10 @@ static void atmel_ac97c_remove(struct platform_device *pdev)
 	ac97c_writel(chip, COMR, 0);
 	ac97c_writel(chip, MR,   0);
 
+	free_irq(chip->irq, chip);
 	clk_disable_unprepare(chip->pclk);
 	clk_put(chip->pclk);
 	iounmap(chip->regs);
-	free_irq(chip->irq, chip);
 
 	snd_card_free(card);
 }
-- 
2.43.0



      parent reply	other threads:[~2026-08-15 16:27 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-08-15 16:27 [PATCH 0/2] ASoC: atmel: ac97c: Fix IRQ handling sequences Manish Baing
2026-08-15 16:27 ` [PATCH 1/2] ASoC: sound: atmel: ac97c: Fix IRQ handler null pointer dereference Manish Baing
2026-08-15 16:27 ` Manish Baing [this message]

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