ACPI: custom_method: fix memory leaks

In cm_write(), 'buf' is allocated through kzalloc(). In the following
execution, if an error occurs, 'buf' is not deallocated, leading to memory
leaks. To fix this issue, free 'buf' before returning the error.

Fixes: 526b4af47f44 ("ACPI: Split out custom_method functionality into an own driver")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c
index b2ef4c2ec955..fd66a736621c 100644
--- a/drivers/acpi/custom_method.c
+++ b/drivers/acpi/custom_method.c
@@ -49,8 +49,10 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf,
         if ((*ppos > max_size) ||
             (*ppos + count > max_size) ||
             (*ppos + count < count) ||
-            (count > uncopied_bytes))
+            (count > uncopied_bytes)) {
+                kfree(buf);
                 return -EINVAL;
+        }
 
         if (copy_from_user(buf + (*ppos), user_buf, count)) {
                 kfree(buf);
@@ -70,6 +72,7 @@ static ssize_t cm_write(struct file *file, const char __user * user_buf,
                 add_taint(TAINT_OVERRIDDEN_ACPI_TABLE, LOCKDEP_NOW_UNRELIABLE);
         }
 
+        kfree(buf);
         return count;
 }