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From: Zhang Rui <rui.zhang@intel.com>
To: linux@roeck-us.net,
	jdelvare@suse.com
Cc: fenghua.yu@intel.com,
	linux-hwmon@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH V2 01/11] hwmon: (coretemp) Fix out-of-bounds memory access
Date: Fri,  2 Feb 2024 17:21:34 +0800
Message-Id: <20240202092144.71180-2-rui.zhang@intel.com>
In-Reply-To: <20240202092144.71180-1-rui.zhang@intel.com>
References: <20240202092144.71180-1-rui.zhang@intel.com>
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Fix a bug that pdata->cpu_map[] is set before out-of-bounds check.
The problem might be triggered on systems with more than 128 cores per
package.

Fixes: 7108b80a542b ("hwmon/coretemp: Handle large core ID value")
Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Cc: <stable@vger.kernel.org>
---
 drivers/hwmon/coretemp.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
index ba82d1e79c13..e78c76919111 100644
--- a/drivers/hwmon/coretemp.c
+++ b/drivers/hwmon/coretemp.c
@@ -509,18 +509,14 @@ static int create_core_data(struct platform_device *pdev, unsigned int cpu,
 	if (pkg_flag) {
 		attr_no = PKG_SYSFS_ATTR_NO;
 	} else {
-		index = ida_alloc(&pdata->ida, GFP_KERNEL);
+		index = ida_alloc_max(&pdata->ida, NUM_REAL_CORES - 1, GFP_KERNEL);
 		if (index < 0)
 			return index;
+
 		pdata->cpu_map[index] = topology_core_id(cpu);
 		attr_no = index + BASE_SYSFS_ATTR_NO;
 	}
 
-	if (attr_no > MAX_CORE_DATA - 1) {
-		err = -ERANGE;
-		goto ida_free;
-	}
-
 	tdata = init_temp_data(cpu, pkg_flag);
 	if (!tdata) {
 		err = -ENOMEM;
-- 
2.34.1