CVE-2022-48921

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The issue is related to a synchronization error in the reweight entity() function of the Linux kernel's sched component, which can cause a null pointer dereference. This occurs due to a race between sched post fork() and setpriority(PRIO PGRP) within a thread group. The scenario involves a main process spawning new threads that call setpriority(PRIO PGRP, 0, -20), wait, and exit. For each new thread, copy process() is invoked, adding a new task struct and calling sched post fork(). If setpriority(PRIO PGRP) and set one prio() are called for a thread being created by copy process() before sched post fork() is executed, it triggers a null pointer dereference in reweight entity(). This is because reweight entity() tries to access the run queue pointer, which hasn't been set. The exploitation of this issue may allow an attacker to impact the confidentiality, integrity, and availability of the system.

Recommendations To fix the issue, remove the update load param from the update load param() function and call reweight task() only if the task flag doesn't have the TASK NEW flag set. At the moment, there is no information about a newer version that contains a fix for this vulnerability.