Logic bug in the Linux kernel's __ptrace_may_access() function (CVE-2026-46333)
Summary
Qualys reports a logic bug in the Linux kernel __ptrace_may_access() (CVE-2026-46333) enabling local privilege escalation via pidfd_getfd. The issue bypasses the dumpable flag when a process's mm pointer is NULL after exit, allowing an attacker to leak or steal resources from a dying process. The advisory details several exploitation case studies (chage, ssh-keysign, pkexec, accounts-daemon) and outlines mitigation and timeline.