2020-08-11 12:32:07

by Madhuparna Bhowmik

Subject: [PATCH] drivers: crypto: picoxcell_crypto: Fix potential race condition bug

From: Madhuparna Bhowmik <[email protected]>

engine->stat_irq_thresh was initialized after device_create_file() in
the probe function, the initialization may race with call to
spacc_stat_irq_thresh_store() which updates engine->stat_irq_thresh,
therefore initialize it before creating the file in probe function.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Madhuparna Bhowmik <[email protected]>
---
drivers/crypto/picoxcell_crypto.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/picoxcell_crypto.c b/drivers/crypto/picoxcell_crypto.c
index dac6eb37fff9..fb34bf92861d 100644
--- a/drivers/crypto/picoxcell_crypto.c
+++ b/drivers/crypto/picoxcell_crypto.c
@@ -1685,11 +1685,6 @@ static int spacc_probe(struct platform_device *pdev)
goto err_clk_put;
}

- ret = device_create_file(&pdev->dev, &dev_attr_stat_irq_thresh);
- if (ret)
- goto err_clk_disable;
-
-
/*
* Use an IRQ threshold of 50% as a default. This seems to be a
* reasonable trade off of latency against throughput but can be
@@ -1697,6 +1692,10 @@ static int spacc_probe(struct platform_device *pdev)
*/
engine->stat_irq_thresh = (engine->fifo_sz / 2);

+ ret = device_create_file(&pdev->dev, &dev_attr_stat_irq_thresh);
+ if (ret)
+ goto err_clk_disable;
+
/*
* Configure the interrupts. We only use the STAT_CNT interrupt as we
* only submit a new packet for processing when we complete another in
--
2.17.1

2020-08-13 11:35:48

by Jamie Iles

Subject: Re: [PATCH] drivers: crypto: picoxcell_crypto: Fix potential race condition bug

On Tue, Aug 11, 2020 at 06:00:24PM +0530, [email protected] wrote:
> From: Madhuparna Bhowmik <[email protected]>
>
> engine->stat_irq_thresh was initialized after device_create_file() in
> the probe function, the initialization may race with call to
> spacc_stat_irq_thresh_store() which updates engine->stat_irq_thresh,
> therefore initialize it before creating the file in probe function.
>
> Found by Linux Driver Verification project (linuxtesting.org).
>
> Signed-off-by: Madhuparna Bhowmik <[email protected]>

Acked-by: Jamie Iles <[email protected]>

Thanks!