From 64f4a62e3b17f1e473f971127c2924cae42afc82 Mon Sep 17 00:00:00 2001

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

Date: Tue, 11 Aug 2020 18:00:24 +0530

Subject: [PATCH] crypto: picoxcell - Fix potential race condition bug

Git-commit: 64f4a62e3b17f1e473f971127c2924cae42afc82

References: git-fixes

Patch-mainline: v5.10-rc1

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).

Fixes: ce92136843cb ("crypto: picoxcell - add support for the...")

Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

Acked-by: Jamie Iles <jamie@jamieiles.com>

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

Signed-off-by: Oliver Neukum <oneukum@suse.com>

---

 drivers/crypto/picoxcell_crypto.c |    9 ++++-----

 1 file changed, 4 insertions(+), 5 deletions(-)

--- a/drivers/crypto/picoxcell_crypto.c

+++ b/drivers/crypto/picoxcell_crypto.c

@@ -1701,11 +1701,6 @@ static int spacc_probe(struct platform_d

 		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

@@ -1713,6 +1708,10 @@ static int spacc_probe(struct platform_d

 	 */

 	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