A use-after-free vulnerability was found in the AMD TEE driver in the Linux kernel. The flaw occurs from a race condition in the `amdtee_open_session()` function, where the session is marked as active in `sess->sess_mask` before the corresponding `sess` structure is fully initialized. If a parallel thread invokes `amdtee_close_session()` during this window of time, it can lead to the structure being freed prematurely. This can lead to system instability, a denial of service, or remote code execution.
In the Linux kernel, the following vulnerability has been resolved:
tee: amdtee: fix race condition in amdtee_open_session
There is a potential race condition in amdtee_open_session that may
lead to use-after-free. For instance, in amdtee_open_session() after
sess->sess_mask is set, and before setting:
sess->session_info[i] = session_info;
if amdtee_close_session() closes this same session, then 'sess' data
structure will be released, causing kernel panic when 'sess' is
accessed within amdtee_open_session().
The solution is to set the bit sess->sess_mask as the last step in
amdtee_open_session().
In the Linux kernel, the following vulnerability has been resolved: tee: amdtee: fix race condition in amdtee_open_session There is a potential race condition in amdtee_open_session that may lead to use-after-free. For instance, in amdtee_open_session() after sess->sess_mask is set, and before setting: sess->session_info[i] = session_info; if amdtee_close_session() closes this same session, then 'sess' data structure will be released, causing kernel panic when 'sess' is accessed within amdtee_open_session(). The solution is to set the bit sess->sess_mask as the last step in amdtee_open_session().