2022-07-15 07:29:05

by Gaosheng Cui

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

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 <[email protected]>
---
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 = {
--
2.25.1

2022-08-18 01:51:46

by Gaosheng Cui

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

PING

?? 2022/7/15 15:11, Gaosheng Cui д??:
> 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 <[email protected]>
> ---
> 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 = {