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| author | Yang Yingliang <yangyingliang@huawei.com> | 2022-11-14 13:26:24 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-03-11 15:55:20 +0300 |
| commit | 2ea7195b195009ecf0046e55361f393ba96d02db (patch) | |
| tree | 91f26312b5a39a79412d3c963145d13b955bed38 | |
| parent | 26ec45f1c504e15268383019df139d7983f1e67f (diff) | |
| download | linux-2ea7195b195009ecf0046e55361f393ba96d02db.tar.xz | |
ubi: Fix possible null-ptr-deref in ubi_free_volume()
[ Upstream commit c15859bfd326c10230f09cb48a17f8a35f190342 ]
It willl cause null-ptr-deref in the following case:
uif_init()
ubi_add_volume()
cdev_add() -> if it fails, call kill_volumes()
device_register()
kill_volumes() -> if ubi_add_volume() fails call this function
ubi_free_volume()
cdev_del()
device_unregister() -> trying to delete a not added device,
it causes null-ptr-deref
So in ubi_free_volume(), it delete devices whether they are added
or not, it will causes null-ptr-deref.
Handle the error case whlie calling ubi_add_volume() to fix this
problem. If add volume fails, set the corresponding vol to null,
so it can not be accessed in kill_volumes() and release the
resource in ubi_add_volume() error path.
Fixes: 801c135ce73d ("UBI: Unsorted Block Images")
Suggested-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Zhihao Cheng <chengzhihao1@huawei.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/mtd/ubi/build.c | 1 | ||||
| -rw-r--r-- | drivers/mtd/ubi/vmt.c | 12 |
2 files changed, 7 insertions, 6 deletions
diff --git a/drivers/mtd/ubi/build.c b/drivers/mtd/ubi/build.c index 2178eb4115b3..7f65af169751 100644 --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -468,6 +468,7 @@ static int uif_init(struct ubi_device *ubi) err = ubi_add_volume(ubi, ubi->volumes[i]); if (err) { ubi_err(ubi, "cannot add volume %d", i); + ubi->volumes[i] = NULL; goto out_volumes; } } diff --git a/drivers/mtd/ubi/vmt.c b/drivers/mtd/ubi/vmt.c index 9fbc64b997ce..2c867d16f89f 100644 --- a/drivers/mtd/ubi/vmt.c +++ b/drivers/mtd/ubi/vmt.c @@ -582,6 +582,7 @@ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol) if (err) { ubi_err(ubi, "cannot add character device for volume %d, error %d", vol_id, err); + vol_release(&vol->dev); return err; } @@ -592,15 +593,14 @@ int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol) vol->dev.groups = volume_dev_groups; dev_set_name(&vol->dev, "%s_%d", ubi->ubi_name, vol->vol_id); err = device_register(&vol->dev); - if (err) - goto out_cdev; + if (err) { + cdev_del(&vol->cdev); + put_device(&vol->dev); + return err; + } self_check_volumes(ubi); return err; - -out_cdev: - cdev_del(&vol->cdev); - return err; } /** |