[PATCH -next] mtd/ftl: Fix uaf in ftl_remove_dev()

[cuigaosheng]

PING

在 2022/7/15 15:11, Gaosheng Cui 写道:
> del_mtd_blktrans_dev will reclaim the resources of mtd_blktrans_dev,
> and call kfree(dev) in blktrans_dev_put to release the memory of
> mtd_blktrans_dev, so when ftl_freepart reclaims the memory of other
> member pointers of the partition_t, it will trigger the uaf problem,
> Fix it by moving ftl_freepart in front of del_mtd_blktrans_dev.
>
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Gaosheng Cui <cuigaosheng1 at huawei.com>
> ---
>   drivers/mtd/ftl.c | 6 +++++-
>   1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/ftl.c b/drivers/mtd/ftl.c
> index 200271bdc7aa..bec56070039d 100644
> --- a/drivers/mtd/ftl.c
> +++ b/drivers/mtd/ftl.c
> @@ -1039,8 +1039,12 @@ static void ftl_add_mtd(struct mtd_blktrans_ops *tr, struct mtd_info *mtd)
>   
>   static void ftl_remove_dev(struct mtd_blktrans_dev *dev)
>   {
> +	struct partition_t *partition;
> +
> +	partition = container_of(dev, struct partition_t, mbd);
> +
> +	ftl_freepart(partition);
>   	del_mtd_blktrans_dev(dev);
> -	ftl_freepart((partition_t *)dev);
>   }
>   
>   static struct mtd_blktrans_ops ftl_tr = {