A use-after-free vulnerability in the Linux Kernel Performance Events system can be exploited to achieve local privilege escalation.

The perf_group_detach function did not check the event's siblings' attach_state before calling add_event_to_groups(), but remove_on_exec made it possible to call list_del_event() on before detaching from their group, making it possible to use a dangling pointer causing a use-after-free vulnerability.

We recommend upgrading past commit fd0815f632c24878e325821943edccc7fde947a2.

References

• https://nvd.nist.gov/vuln/detail/CVE-2023-2235
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fd0815f632c24878e325821943edccc7fde947a2
• https://kernel.dance/fd0815f632c24878e325821943edccc7fde947a2