Patch "hwmon: (lm95234) Fix underflows seen when writing limit attributes" has been added to the 5.15-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    hwmon: (lm95234) Fix underflows seen when writing limit attributes

to the 5.15-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     hwmon-lm95234-fix-underflows-seen-when-writing-limit.patch
and it can be found in the queue-5.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 8857eb2dd85ab5f2c1e4103727eab07ee3966101
Author: Guenter Roeck <linux@xxxxxxxxxxxx>
Date:   Sat Jul 6 23:48:42 2024 -0700

    hwmon: (lm95234) Fix underflows seen when writing limit attributes
    
    [ Upstream commit af64e3e1537896337405f880c1e9ac1f8c0c6198 ]
    
    DIV_ROUND_CLOSEST() after kstrtol() results in an underflow if a large
    negative number such as -9223372036854775808 is provided by the user.
    Fix it by reordering clamp_val() and DIV_ROUND_CLOSEST() operations.
    
    Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/hwmon/lm95234.c b/drivers/hwmon/lm95234.c
index ac169a994ae0..db2aecdfbd17 100644
--- a/drivers/hwmon/lm95234.c
+++ b/drivers/hwmon/lm95234.c
@@ -301,7 +301,8 @@ static ssize_t tcrit2_store(struct device *dev, struct device_attribute *attr,
 	if (ret < 0)
 		return ret;
 
-	val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, index ? 255 : 127);
+	val = DIV_ROUND_CLOSEST(clamp_val(val, 0, (index ? 255 : 127) * 1000),
+				1000);
 
 	mutex_lock(&data->update_lock);
 	data->tcrit2[index] = val;
@@ -350,7 +351,7 @@ static ssize_t tcrit1_store(struct device *dev, struct device_attribute *attr,
 	if (ret < 0)
 		return ret;
 
-	val = clamp_val(DIV_ROUND_CLOSEST(val, 1000), 0, 255);
+	val = DIV_ROUND_CLOSEST(clamp_val(val, 0, 255000), 1000);
 
 	mutex_lock(&data->update_lock);
 	data->tcrit1[index] = val;
@@ -391,7 +392,7 @@ static ssize_t tcrit1_hyst_store(struct device *dev,
 	if (ret < 0)
 		return ret;
 
-	val = DIV_ROUND_CLOSEST(val, 1000);
+	val = DIV_ROUND_CLOSEST(clamp_val(val, -255000, 255000), 1000);
 	val = clamp_val((int)data->tcrit1[index] - val, 0, 31);
 
 	mutex_lock(&data->update_lock);
@@ -431,7 +432,7 @@ static ssize_t offset_store(struct device *dev, struct device_attribute *attr,
 		return ret;
 
 	/* Accuracy is 1/2 degrees C */
-	val = clamp_val(DIV_ROUND_CLOSEST(val, 500), -128, 127);
+	val = DIV_ROUND_CLOSEST(clamp_val(val, -64000, 63500), 500);
 
 	mutex_lock(&data->update_lock);
 	data->toffset[index] = val;