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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Wenwen Wang <wenwen@cs.uga.edu>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Sasha Levin <sashal@kernel.org>, linux-acpi@vger.kernel.org
Subject: [PATCH AUTOSEL 5.3 157/203] ACPI: custom_method: fix memory leaks
Date:   Sun, 22 Sep 2019 14:43:03 -0400
Message-Id: <20190922184350.30563-157-sashal@kernel.org>
In-Reply-To: <20190922184350.30563-1-sashal@kernel.org>
References: <20190922184350.30563-1-sashal@kernel.org>
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From: Wenwen Wang <wenwen@cs.uga.edu>

[ Upstream commit 03d1571d9513369c17e6848476763ebbd10ec2cb ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 b2ef4c2ec955d..fd66a736621cf 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;
 }
 
-- 
2.20.1