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From:   "Lee, Chun-Yi" <joeyli.kernel@gmail.com>
To:     "Rafael J . Wysocki" <rafael@kernel.org>,
        Daniel Lezcano <daniel.lezcano@linaro.org>
Cc:     Amit Kucheria <amitk@kernel.org>, Zhang Rui <rui.zhang@intel.com>,
        linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        "Lee, Chun-Yi" <jlee@suse.com>
Subject: [PATCH] thermal/int340x_thermal: handle data_vault when the value is ZERO_SIZE_PTR
Date:   Mon,  8 Aug 2022 21:21:58 +0800
Message-Id: <20220808132158.24099-1-jlee@suse.com>
Precedence: bulk

In some case, the GDDV returns a package with a buffer which has
zero length. It causes that kmemdup() returns ZERO_SIZE_PTR (0x10).

Then the data_vault_read() got NULL point dereference problem when
accessing the 0x10 value in data_vault.

[   71.024560] BUG: kernel NULL pointer dereference, address:
0000000000000010

This patch uses ZERO_OR_NULL_PTR() for checking ZERO_SIZE_PTR or
NULL value in data_vault.

Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
---
 drivers/thermal/intel/int340x_thermal/int3400_thermal.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
index 80d4e0676083..365489bf4b8c 100644
--- a/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
+++ b/drivers/thermal/intel/int340x_thermal/int3400_thermal.c
@@ -527,7 +527,7 @@ static void int3400_setup_gddv(struct int3400_thermal_priv *priv)
 	priv->data_vault = kmemdup(obj->package.elements[0].buffer.pointer,
 				   obj->package.elements[0].buffer.length,
 				   GFP_KERNEL);
-	if (!priv->data_vault)
+	if (ZERO_OR_NULL_PTR(priv->data_vault))
 		goto out_free;
 
 	bin_attr_data_vault.private = priv->data_vault;
@@ -597,7 +597,7 @@ static int int3400_thermal_probe(struct platform_device *pdev)
 			goto free_imok;
 	}
 
-	if (priv->data_vault) {
+	if (!ZERO_OR_NULL_PTR(priv->data_vault)) {
 		result = sysfs_create_group(&pdev->dev.kobj,
 					    &data_attribute_group);
 		if (result)
@@ -615,7 +615,8 @@ static int int3400_thermal_probe(struct platform_device *pdev)
 free_sysfs:
 	cleanup_odvp(priv);
 	if (priv->data_vault) {
-		sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
+		if (!ZERO_OR_NULL_PTR(priv->data_vault))
+			sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
 		kfree(priv->data_vault);
 	}
 free_uuid:
@@ -647,7 +648,7 @@ static int int3400_thermal_remove(struct platform_device *pdev)
 	if (!priv->rel_misc_dev_res)
 		acpi_thermal_rel_misc_device_remove(priv->adev->handle);
 
-	if (priv->data_vault)
+	if (!ZERO_OR_NULL_PTR(priv->data_vault))
 		sysfs_remove_group(&pdev->dev.kobj, &data_attribute_group);
 	sysfs_remove_group(&pdev->dev.kobj, &uuid_attribute_group);
 	sysfs_remove_group(&pdev->dev.kobj, &imok_attribute_group);
-- 
2.26.2