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From:   Wenwen Wang <wenwen@cs.uga.edu>
To:     Wenwen Wang <wenwen@cs.uga.edu>
Cc:     Miquel Raynal <miquel.raynal@bootlin.com>,
        Richard Weinberger <richard@nod.at>,
        David Woodhouse <dwmw2@infradead.org>,
        Brian Norris <computersforpeace@gmail.com>,
        Marek Vasut <marek.vasut@gmail.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        Boris Brezillon <bbrezillon@kernel.org>,
        Frieder Schrempf <frieder.schrempf@kontron.de>,
        Thomas Gleixner <tglx@linutronix.de>,
        Kate Stewart <kstewart@linuxfoundation.org>,
        Randy Dunlap <rdunlap@infradead.org>,
        linux-mtd@lists.infradead.org (open list:NAND FLASH SUBSYSTEM),
        linux-kernel@vger.kernel.org (open list)
Subject: [PATCH v2] mtd: rawnand: Fix a memory leak bug
Date:   Sun, 18 Aug 2019 21:46:04 -0500
Message-Id: <1566182765-7150-1-git-send-email-wenwen@cs.uga.edu>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

In nand_scan_bbt(), a temporary buffer 'buf' is allocated through
vmalloc(). However, if check_create() fails, 'buf' is not deallocated,
leading to a memory leak bug. To fix this issue, free 'buf' before
returning the error.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
---
 drivers/mtd/nand/raw/nand_bbt.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/raw/nand_bbt.c b/drivers/mtd/nand/raw/nand_bbt.c
index 2ef15ef..96045d6 100644
--- a/drivers/mtd/nand/raw/nand_bbt.c
+++ b/drivers/mtd/nand/raw/nand_bbt.c
@@ -1232,7 +1232,7 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd)
 	if (!td) {
 		if ((res = nand_memory_bbt(this, bd))) {
 			pr_err("nand_bbt: can't scan flash and build the RAM-based BBT\n");
-			goto err;
+			goto err_free_bbt;
 		}
 		return 0;
 	}
@@ -1245,7 +1245,7 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd)
 	buf = vmalloc(len);
 	if (!buf) {
 		res = -ENOMEM;
-		goto err;
+		goto err_free_bbt;
 	}
 
 	/* Is the bbt at a given page? */
@@ -1258,7 +1258,7 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd)
 
 	res = check_create(this, buf, bd);
 	if (res)
-		goto err;
+		goto err_free_buf;
 
 	/* Prevent the bbt regions from erasing / writing */
 	mark_bbt_region(this, td);
@@ -1268,7 +1268,9 @@ static int nand_scan_bbt(struct nand_chip *this, struct nand_bbt_descr *bd)
 	vfree(buf);
 	return 0;
 
-err:
+err_free_buf:
+	vfree(buf);
+err_free_bbt:
 	kfree(this->bbt);
 	this->bbt = NULL;
 	return res;
-- 
2.7.4