Patch "platform/chrome: fix double-free in chromeos_laptop_prepare()" has been added to the 5.10-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

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

    platform/chrome: fix double-free in chromeos_laptop_prepare()

to the 5.10-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:
     platform-chrome-fix-double-free-in-chromeos_laptop_p.patch
and it can be found in the queue-5.10 subdirectory.

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



commit 49b2857f75b477575e20b3da873e75cdfc4d13a3
Author: Rustam Subkhankulov <subkhankulov@xxxxxxxxx>
Date:   Sun Aug 14 01:08:43 2022 +0300

    platform/chrome: fix double-free in chromeos_laptop_prepare()
    
    [ Upstream commit 6ad4194d6a1e1d11b285989cd648ef695b4a93c0 ]
    
    If chromeos_laptop_prepare_i2c_peripherals() fails after allocating memory
    for 'cros_laptop->i2c_peripherals', this memory is freed at 'err_out' label
    and nonzero value is returned. Then chromeos_laptop_destroy() is called,
    resulting in double-free error.
    
    Found by Linux Verification Center (linuxtesting.org) with SVACE.
    
    Signed-off-by: Rustam Subkhankulov <subkhankulov@xxxxxxxxx>
    Fixes: 5020cd29d8bf ("platform/chrome: chromeos_laptop - supply properties for ACPI devices")
    Reviewed-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
    Signed-off-by: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
    Link: https://lore.kernel.org/r/20220813220843.2373004-1-subkhankulov@xxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/platform/chrome/chromeos_laptop.c b/drivers/platform/chrome/chromeos_laptop.c
index 472a03daa869..109c191d35cf 100644
--- a/drivers/platform/chrome/chromeos_laptop.c
+++ b/drivers/platform/chrome/chromeos_laptop.c
@@ -718,6 +718,7 @@ static int __init
 chromeos_laptop_prepare_i2c_peripherals(struct chromeos_laptop *cros_laptop,
 					const struct chromeos_laptop *src)
 {
+	struct i2c_peripheral *i2c_peripherals;
 	struct i2c_peripheral *i2c_dev;
 	struct i2c_board_info *info;
 	int i;
@@ -726,17 +727,15 @@ chromeos_laptop_prepare_i2c_peripherals(struct chromeos_laptop *cros_laptop,
 	if (!src->num_i2c_peripherals)
 		return 0;
 
-	cros_laptop->i2c_peripherals = kmemdup(src->i2c_peripherals,
-					       src->num_i2c_peripherals *
-						sizeof(*src->i2c_peripherals),
-					       GFP_KERNEL);
-	if (!cros_laptop->i2c_peripherals)
+	i2c_peripherals = kmemdup(src->i2c_peripherals,
+					      src->num_i2c_peripherals *
+					  sizeof(*src->i2c_peripherals),
+					  GFP_KERNEL);
+	if (!i2c_peripherals)
 		return -ENOMEM;
 
-	cros_laptop->num_i2c_peripherals = src->num_i2c_peripherals;
-
-	for (i = 0; i < cros_laptop->num_i2c_peripherals; i++) {
-		i2c_dev = &cros_laptop->i2c_peripherals[i];
+	for (i = 0; i < src->num_i2c_peripherals; i++) {
+		i2c_dev = &i2c_peripherals[i];
 		info = &i2c_dev->board_info;
 
 		error = chromeos_laptop_setup_irq(i2c_dev);
@@ -754,16 +753,19 @@ chromeos_laptop_prepare_i2c_peripherals(struct chromeos_laptop *cros_laptop,
 		}
 	}
 
+	cros_laptop->i2c_peripherals = i2c_peripherals;
+	cros_laptop->num_i2c_peripherals = src->num_i2c_peripherals;
+
 	return 0;
 
 err_out:
 	while (--i >= 0) {
-		i2c_dev = &cros_laptop->i2c_peripherals[i];
+		i2c_dev = &i2c_peripherals[i];
 		info = &i2c_dev->board_info;
 		if (info->properties)
 			property_entries_free(info->properties);
 	}
-	kfree(cros_laptop->i2c_peripherals);
+	kfree(i2c_peripherals);
 	return error;
 }