Re: [PATCH] mtd: rawnand: meson: Fix a potential double free issue

From: Liang Yang
Date: Thu May 26 2022 - 01:36:23 EST


Hi Christophe,

On 2022/5/21 0:41, Christophe JAILLET wrote:
[ EXTERNAL EMAIL ]

When meson_nfc_nand_chip_cleanup() is called, it will call:
meson_nfc_free_buffer(&meson_chip->nand);
nand_cleanup(&meson_chip->nand);

nand_cleanup() in turn will call nand_detach() which calls the
.detach_chip() which is here meson_nand_detach_chip().

meson_nand_detach_chip() already calls meson_nfc_free_buffer(), so we
could double free some memory.

Fix it by removing the unneeded explicit call to meson_nfc_free_buffer().

Fixes: 8fae856c5350 ("mtd: rawnand: meson: add support for Amlogic NAND flash controller")
Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx>
---
This patch is speculative, so review with care.
---
drivers/mtd/nand/raw/meson_nand.c | 1 -
1 file changed, 1 deletion(-)

diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
index ac3be92872d0..032180183339 100644
--- a/drivers/mtd/nand/raw/meson_nand.c
+++ b/drivers/mtd/nand/raw/meson_nand.c
@@ -1307,7 +1307,6 @@ static int meson_nfc_nand_chip_cleanup(struct meson_nfc *nfc)
if (ret)
return ret;
- meson_nfc_free_buffer(&meson_chip->nand);
nand_cleanup(&meson_chip->nand);
list_del(&meson_chip->node);
}

Acked-by: Liang Yang <liang.yang@xxxxxxxxxxx>

Thanks,
Liang