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* FAILED: patch "[PATCH] hwmon: (max16065) Use local variable to avoid TOCTOU" failed to apply to 5.10-stable tree
@ 2025-12-29 15:57 gregkh
  2025-12-31 20:41 ` [PATCH 5.10.y 1/2] hwmon: replace snprintf in show functions with sysfs_emit Sasha Levin
  0 siblings, 1 reply; 3+ messages in thread
From: gregkh @ 2025-12-29 15:57 UTC (permalink / raw)
  To: hanguidong02, linux; +Cc: stable


The patch below does not apply to the 5.10-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x b8d5acdcf525f44e521ca4ef51dce4dac403dab4
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025122905-unstable-smuggling-c1a3@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From b8d5acdcf525f44e521ca4ef51dce4dac403dab4 Mon Sep 17 00:00:00 2001
From: Gui-Dong Han <hanguidong02@gmail.com>
Date: Fri, 28 Nov 2025 20:47:09 +0800
Subject: [PATCH] hwmon: (max16065) Use local variable to avoid TOCTOU

In max16065_current_show, data->curr_sense is read twice: once for the
error check and again for the calculation. Since
i2c_smbus_read_byte_data returns negative error codes on failure, if the
data changes to an error code between the check and the use, ADC_TO_CURR
results in an incorrect calculation.

Read data->curr_sense into a local variable to ensure consistency. Note
that data->curr_gain is constant and safe to access directly.

This aligns max16065_current_show with max16065_input_show, which
already uses a local variable for the same reason.

Link: https://lore.kernel.org/all/CALbr=LYJ_ehtp53HXEVkSpYoub+XYSTU8Rg=o1xxMJ8=5z8B-g@mail.gmail.com/
Fixes: f5bae2642e3d ("hwmon: Driver for MAX16065 System Manager and compatibles")
Cc: stable@vger.kernel.org
Signed-off-by: Gui-Dong Han <hanguidong02@gmail.com>
Link: https://lore.kernel.org/r/20251128124709.3876-1-hanguidong02@gmail.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/max16065.c b/drivers/hwmon/max16065.c
index 0ccb5eb596fc..4c9e7892a73c 100644
--- a/drivers/hwmon/max16065.c
+++ b/drivers/hwmon/max16065.c
@@ -216,12 +216,13 @@ static ssize_t max16065_current_show(struct device *dev,
 				     struct device_attribute *da, char *buf)
 {
 	struct max16065_data *data = max16065_update_device(dev);
+	int curr_sense = data->curr_sense;
 
-	if (unlikely(data->curr_sense < 0))
-		return data->curr_sense;
+	if (unlikely(curr_sense < 0))
+		return curr_sense;
 
 	return sysfs_emit(buf, "%d\n",
-			  ADC_TO_CURR(data->curr_sense, data->curr_gain));
+			  ADC_TO_CURR(curr_sense, data->curr_gain));
 }
 
 static ssize_t max16065_limit_store(struct device *dev,


^ permalink raw reply related	[flat|nested] 3+ messages in thread
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2025-12-29 15:57 FAILED: patch "[PATCH] hwmon: (max16065) Use local variable to avoid TOCTOU" failed to apply to 5.10-stable tree gregkh
2025-12-31 20:41 ` [PATCH 5.10.y 1/2] hwmon: replace snprintf in show functions with sysfs_emit Sasha Levin
2025-12-31 20:41   ` [PATCH 5.10.y 2/2] hwmon: (max16065) Use local variable to avoid TOCTOU Sasha Levin

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