linux-kernel - [PATCH 1/3] mmc: sdhci-s3c: fix possible NULL pointer dereference when probed via platform

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20210414151242.102313-1-krzysztof.kozlowski@canonical.com>
Date:   Wed, 14 Apr 2021 17:12:40 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
To:     Ben Dooks <ben-linux@...ff.org>,
        Jaehoon Chung <jh80.chung@...sung.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Ulf Hansson <ulf.hansson@...aro.org>,
        linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Marek Szyprowski <m.szyprowski@...sung.com>,
        Sylwester Nawrocki <snawrocki@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
Subject: [PATCH 1/3] mmc: sdhci-s3c: fix possible NULL pointer dereference when probed via platform

The driver can be matched by legacy platform way or OF-device matching.
In the first case, of_match_node() can return NULL, which immediately
would be dereferenced to get the match data.

Addresses-Coverity: Dereference null return value
Fixes: cd1b00eb24b0 ("mmc: sdhci-s3c: Add device tree support")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...onical.com>
---

Not tested on HW, but the code should be equivalent (plus safer).

 drivers/mmc/host/sdhci-s3c.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index f48a788a9d3d..8e1dca625620 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -20,6 +20,7 @@
 #include <linux/gpio.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 #include <linux/of_gpio.h>
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
@@ -461,19 +462,12 @@ static int sdhci_s3c_parse_dt(struct device *dev,
 }
 #endif
 
-#ifdef CONFIG_OF
-static const struct of_device_id sdhci_s3c_dt_match[];
-#endif
-
 static inline struct sdhci_s3c_drv_data *sdhci_s3c_get_driver_data(
 			struct platform_device *pdev)
 {
 #ifdef CONFIG_OF
-	if (pdev->dev.of_node) {
-		const struct of_device_id *match;
-		match = of_match_node(sdhci_s3c_dt_match, pdev->dev.of_node);
-		return (struct sdhci_s3c_drv_data *)match->data;
-	}
+	if (pdev->dev.of_node)
+		return (struct sdhci_s3c_drv_data *)of_device_get_match_data(&pdev->dev);
 #endif
 	return (struct sdhci_s3c_drv_data *)
 			platform_get_device_id(pdev)->driver_data;
-- 
2.25.1