In the Linux kernel, the following vulnerability has been resolved: binder: fix race between mmput() and do_exit() Task A calls binder_update_page_range() to allocate and insert pages on a remote address space from Task B. For this, Task A pins the remote mm via mmget_not_zero() first. This can race with Task B do_exit() and the final mmput() refcount decrement will come from Task A. Task A | Task B ------------------+------------------ mmget_not_zero() | | do_exit() | exit_mm() | mmput() mmput() | exit_mmap() | remove_vma() | fput() | In this case, the work of ____fput() from Task B is queued up in Task A as TWA_RESUME. So in theory, Task A returns to userspace and the cleanup work gets executed. However, Task A instead sleep, waiting for a reply from Task B that never comes (it's dead). This means the binder_deferred_release() is blocked until an unrelated binder event forces Task A to go back to userspace. All the associated death notifications will also be delayed until then. In order to fix this use mmput_async() that will schedule the work in the corresponding mm->async_put_work WQ instead of Task A.

ID	Name	Product	Family	Severity
195118	Ubuntu 22.04 LTS : Linux kernel (OEM) vulnerabilities (USN-6765-1)	Nessus	Ubuntu Local Security Checks	high
193407	Ubuntu 20.04 LTS : Linux kernel (Xilinx ZynqMP) vulnerabilities (USN-6726-3)	Nessus	Ubuntu Local Security Checks	high
193376	Ubuntu 20.04 LTS : Linux kernel (IoT) vulnerabilities (USN-6726-2)	Nessus	Ubuntu Local Security Checks	high
193375	Ubuntu 20.04 LTS / 22.04 LTS : Linux kernel (AWS) vulnerabilities (USN-6725-2)	Nessus	Ubuntu Local Security Checks	critical
193084	Ubuntu 20.04 LTS / 22.04 LTS : Linux kernel vulnerabilities (USN-6725-1)	Nessus	Ubuntu Local Security Checks	critical
193081	Ubuntu 18.04 LTS / 20.04 LTS : Linux kernel vulnerabilities (USN-6726-1)	Nessus	Ubuntu Local Security Checks	high

Detections

Analytics

CVE-2023-52609

high

Tenable Plugins

high

high

high

critical

critical

high