[RESEND PATCH] mtd: phram: fix a double free issue in error path

* [RESEND PATCH] mtd: phram: fix a double free issue in error path
@ 2020-03-18 15:31 Wen Yang
  2020-03-24 22:05 ` Miquel Raynal
  0 siblings, 1 reply; 2+ messages in thread
From: Wen Yang @ 2020-03-18 15:31 UTC (permalink / raw)
  To: Joern Engel, Miquel Raynal, Richard Weinberger, Vignesh Raghavendra
  Cc: linux-mtd, Wen Yang, linux-kernel

The variable 'name' is released multiple times in the error path,
which may cause double free issues.
This problem is avoided by adding a goto label to release the mem
uniformly. And this change also makes the code a bit more cleaner.

Fixes: 4f678a58d335 ("mtd: fix memory leaks in phram_setup")
Signed-off-by: Wen Yang <wenyang@linux.alibaba.com>
Cc: Joern Engel <joern@lazybastard.org>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Vignesh Raghavendra <vigneshr@ti.com>
Cc: linux-mtd@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
---
 drivers/mtd/devices/phram.c | 15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c
index 931e5c2481b5..b50ec7ecd10c 100644
--- a/drivers/mtd/devices/phram.c
+++ b/drivers/mtd/devices/phram.c
@@ -243,22 +243,25 @@ static int phram_setup(const char *val)
 
 	ret = parse_num64(&start, token[1]);
 	if (ret) {
-		kfree(name);
 		parse_err("illegal start address\n");
+		goto error;
 	}
 
 	ret = parse_num64(&len, token[2]);
 	if (ret) {
-		kfree(name);
 		parse_err("illegal device length\n");
+		goto error;
 	}
 
 	ret = register_device(name, start, len);
-	if (!ret)
-		pr_info("%s device: %#llx at %#llx\n", name, len, start);
-	else
-		kfree(name);
+	if (ret)
+		goto error;
+
+	pr_info("%s device: %#llx at %#llx\n", name, len, start);
+	return 0;
 
+error:
+	kfree(name);
 	return ret;
 }
 
-- 
2.23.0


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