CVE-2019-3901

A race condition in perf_event_open() allows local attackers to leak
sensitive data from setuid programs. As no relevant locks (in particular
the cred_guard_mutex) are held during the ptrace_may_access() call, it is
possible for the specified target task to perform an execve() syscall with
setuid execution before perf_event_alloc() actually attaches to it,
allowing an attacker to bypass the ptrace_may_access() check and the
perf_event_exit_task(current) call that is performed in
install_exec_creds() during privileged execve() calls. This issue affects
kernel versions before 4.8.

Bugs

• <https://bugs.chromium.org/p/project-zero/issues/detail?id=807&gt;