CVE-2023-54087

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

ubi: Fix possible null-ptr-deref in ubi_free_volume()

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.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References