title: tee: amdtee: fix use-after-free vulnerability in amdtee_close_session
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.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 757cc3e9ff1d, lessThan: da7ce52a2f6c, status: affected, versionType: git
version: 757cc3e9ff1d, lessThan: 1680c82929bc, status: affected, versionType: git
version: 757cc3e9ff1d, lessThan: 60c3e7a00db9, status: affected, versionType: git
version: 757cc3e9ff1d, lessThan: 1c95574350cd, status: affected, versionType: git
version: 757cc3e9ff1d, lessThan: f4384b3e54ea, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.6, status: affected
version: 0, lessThan: 5.6, status: unaffected, versionType: custom
version: 5.10.199, lessThanOrEqual: 5.10.*, status: unaffected, versionType: custom
version: 5.15.136, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.59, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.5.8, lessThanOrEqual: 6.5.*, status: unaffected, versionType: custom
version: 6.6, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
