Patch "mtd: phram: fix a double free issue in error path" has been added to the 5.4-stable tree

Patch "mtd: phram: fix a double free issue in error path" has been added to the 5.4-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    mtd: phram: fix a double free issue in error path

to the 5.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mtd-phram-fix-a-double-free-issue-in-error-path.patch
and it can be found in the queue-5.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From 49c64df880570034308e4a9a49c4bc95cf8cdb33 Mon Sep 17 00:00:00 2001
From: Wen Yang <wenyang@linux.alibaba.com>
Date: Wed, 18 Mar 2020 23:31:56 +0800
Subject: mtd: phram: fix a double free issue in error path

From: Wen Yang <wenyang@linux.alibaba.com>

commit 49c64df880570034308e4a9a49c4bc95cf8cdb33 upstream.

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 memory
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
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20200318153156.25612-1-wenyang@linux.alibaba.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/mtd/devices/phram.c |   15 +++++++++------
 1 file changed, 9 insertions(+), 6 deletions(-)

--- 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;
 }
 


Patches currently in stable-queue which might be from wenyang@linux.alibaba.com are

queue-5.4/mtd-phram-fix-a-double-free-issue-in-error-path.patch

______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/