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From:   Wenwen Wang <wenwen@cs.uga.edu>
To:     Wenwen Wang <wenwen@cs.uga.edu>
Cc:     "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Len Brown <lenb@kernel.org>,
        linux-acpi@vger.kernel.org (open list:ACPI),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH] ACPI: custom_method: fix memory leaks
Date:   Fri, 16 Aug 2019 00:08:27 -0500
Message-Id: <1565932107-5864-1-git-send-email-wenwen@cs.uga.edu>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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 <wenwen@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