CVE-2023-52503

/// Technical description

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

tee: amdtee: fix use-after-free vulnerability in amdtee_close_session

There is a potential race condition in amdtee_close_session that may

cause use-after-free in amdtee_open_session. For instance, if a session

has refcount == 1, and one thread tries to free this session via:

kref_put(&sess->refcount, destroy_session);

the reference count will get decremented, and the next step would be to

call destroy_session(). However, if in another thread,

amdtee_open_session() is called before destroy_session() has completed

execution, alloc_session() may return 'sess' that will be freed up

later in destroy_session() leading to use-after-free in

amdtee_open_session.

To fix this issue, treat decrement of sess->refcount and removal of

'sess' from session list in destroy_session() as a critical section, so

that it is executed atomically.

/// 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