[PATCH] ACPI: custom_method: fix memory leaks

[Wenwen Wang]

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.

Signed-off-by: Wenwen Wang <wen...@cs.uga.edu>
---
 drivers/acpi/custom_method.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/custom_method.c b/drivers/acpi/custom_method.c
index b2ef4c2..fd66a73 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;
 }
 
-- 
2.7.4