[PATCH 5.8 105/633] crypto: picoxcell - Fix potential race condition bug

Greg Kroah-Hartman
2020-10-27T17:26:46Z

From: Madhuparna Bhowmik <madhuparnabhowmik10@gmail.com>

[ Upstream commit 64f4a62e3b17f1e473f971127c2924cae42afc82 ]

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: Sasha Levin <sashal@kernel.org>
---
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 7384e91c8b32b..0d32b641a7f9d 100644
--- a/drivers/crypto/picoxcell_crypto.c
+++ b/drivers/crypto/picoxcell_crypto.c
@@ -1666,11 +1666,6 @@ 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
@@ -1678,6 +1673,10 @@ 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
--
2.25.1