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

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@ispras.ru>
Fixes: 5020cd29d8bf ("platform/chrome: chromeos_laptop - supply properties for ACPI devices")
Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220813220843.2373004-1-subkhankulov@ispras.ru

diff --git a/drivers/platform/chrome/chromeos_laptop.c b/drivers/platform/chrome/chromeos_laptop.c
index 4e14b4d6635d765539d186b11738356471c60fa6..a2cdbfbaeae6b0ba7d2961308a0e3f76fd3a58d4 100644 (file)
--- a/drivers/platform/chrome/chromeos_laptop.c
+++ b/drivers/platform/chrome/chromeos_laptop.c
@@ -740,6 +740,7 @@ 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;
@@ -748,17 +749,15 @@ 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);
@@ -775,16 +774,19 @@ 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 (!IS_ERR_OR_NULL(info->fwnode))
                        fwnode_remove_software_node(info->fwnode);
        }
-       kfree(cros_laptop->i2c_peripherals);
+       kfree(i2c_peripherals);
        return error;
 }