[RFC PATCH 2/2] ASoC: atmel: ac97c: Fix use-after-free on driver teardown
Manish Baing
manishbaing2789 at gmail.com
Thu Jun 4 13:36:23 PDT 2026
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 at kernel.org>
Signed-off-by: Manish Baing <manishbaing2789 at 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 cd74395dd222..b9280b644f26 100644
--- a/sound/atmel/ac97c.c
+++ b/sound/atmel/ac97c.c
@@ -790,7 +790,7 @@ 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);
@@ -800,11 +800,12 @@ 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);
@@ -842,10 +843,10 @@ 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
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