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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Guenter Roeck <linux@roeck-us.net>,
        Christophe JAILLET <christophe.jaillet@wanadoo.fr>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.10 381/599] fsi: Aspeed: Fix a potential double free
Date:   Tue,  5 Apr 2022 09:31:15 +0200
Message-Id: <20220405070310.169388127@linuxfoundation.org>
In-Reply-To: <20220405070258.802373272@linuxfoundation.org>
References: <20220405070258.802373272@linuxfoundation.org>
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From: Christophe JAILLET <christophe.jaillet@wanadoo.fr>

[ Upstream commit 83ba7e895debc529803a7a258653f2fe9bf3bf40 ]

A struct device can never be devm_alloc()'ed.
Here, it is embedded in "struct fsi_master", and "struct fsi_master" is
embedded in "struct fsi_master_aspeed".

Since "struct device" is embedded, the data structure embedding it must be
released with the release function, as is already done here.

So use kzalloc() instead of devm_kzalloc() when allocating "aspeed" and
update all error handling branches accordingly.

This prevent a potential double free().

This also fix another issue if opb_readl() fails. Instead of a direct
return, it now jumps in the error handling path.

Fixes: 606397d67f41 ("fsi: Add ast2600 master driver")
Suggested-by: Greg KH <gregkh@linuxfoundation.org>
Suggested-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/2c123f8b0a40dc1a061fae982169fe030b4f47e6.1641765339.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/fsi/fsi-master-aspeed.c | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/fsi/fsi-master-aspeed.c b/drivers/fsi/fsi-master-aspeed.c
index 5d2469d44607..87edc77260d2 100644
--- a/drivers/fsi/fsi-master-aspeed.c
+++ b/drivers/fsi/fsi-master-aspeed.c
@@ -534,25 +534,28 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)
 		return rc;
 	}
 
-	aspeed = devm_kzalloc(&pdev->dev, sizeof(*aspeed), GFP_KERNEL);
+	aspeed = kzalloc(sizeof(*aspeed), GFP_KERNEL);
 	if (!aspeed)
 		return -ENOMEM;
 
 	aspeed->dev = &pdev->dev;
 
 	aspeed->base = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(aspeed->base))
-		return PTR_ERR(aspeed->base);
+	if (IS_ERR(aspeed->base)) {
+		rc = PTR_ERR(aspeed->base);
+		goto err_free_aspeed;
+	}
 
 	aspeed->clk = devm_clk_get(aspeed->dev, NULL);
 	if (IS_ERR(aspeed->clk)) {
 		dev_err(aspeed->dev, "couldn't get clock\n");
-		return PTR_ERR(aspeed->clk);
+		rc = PTR_ERR(aspeed->clk);
+		goto err_free_aspeed;
 	}
 	rc = clk_prepare_enable(aspeed->clk);
 	if (rc) {
 		dev_err(aspeed->dev, "couldn't enable clock\n");
-		return rc;
+		goto err_free_aspeed;
 	}
 
 	rc = setup_cfam_reset(aspeed);
@@ -587,7 +590,7 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)
 	rc = opb_readl(aspeed, ctrl_base + FSI_MVER, &raw);
 	if (rc) {
 		dev_err(&pdev->dev, "failed to read hub version\n");
-		return rc;
+		goto err_release;
 	}
 
 	reg = be32_to_cpu(raw);
@@ -626,6 +629,8 @@ static int fsi_master_aspeed_probe(struct platform_device *pdev)
 
 err_release:
 	clk_disable_unprepare(aspeed->clk);
+err_free_aspeed:
+	kfree(aspeed);
 	return rc;
 }
 
-- 
2.34.1