Commit ca19808b authored by James Kim's avatar James Kim Committed by Miquel Raynal
Browse files

mtd: docg3: fix use-after-free in docg3_release() 



In docg3_release(), the docg3 pointer is obtained from
cascade->floors[0]->priv before the loop that calls
doc_release_device() on each floor. doc_release_device() frees the
docg3 struct via kfree(docg3) at line 1881. After the loop,
docg3->cascade->bch dereferences the already-freed pointer.

Fix this by accessing cascade->bch directly, which is equivalent
since docg3->cascade points back to the same cascade struct, and
is already available as a local variable. This also removes the
now-unused docg3 local variable.

Fixes: c8ae3f74 ("lib/bch: Rework a little bit the exported function names")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJames Kim <james010kim@gmail.com>
Signed-off-by: default avatarMiquel Raynal <miquel.raynal@bootlin.com>
parent e19eaffc

drivers/mtd/devices/docg3.c

+1 −2
Original line number Diff line number Diff line
@@ -2049,7 +2049,6 @@ static int __init docg3_probe(struct platform_device *pdev) 
static void docg3_release(struct platform_device *pdev)

{

	struct docg3_cascade *cascade = platform_get_drvdata(pdev);

	struct docg3 *docg3 = cascade->floors[0]->priv;

	int floor;



	doc_unregister_sysfs(pdev, cascade);
@@ -2057,7 +2056,7 @@ static void docg3_release(struct platform_device *pdev) 
		if (cascade->floors[floor])

			doc_release_device(cascade->floors[floor]);



	bch_free(docg3->cascade->bch);

	bch_free(cascade->bch);

}



#ifdef CONFIG_OF