Race condition in Linux kernel - CVE-2019-3901

Detailed vulnerability description

The vulnerability allows a local authenticated user to gain access to sensitive information.

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.

How to mitigate CVE-2019-3901

Sources

• http://www.securityfocus.com/bid/89937
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-3901
• https://lists.debian.org/debian-lts-announce/2019/05/msg00041.html
• https://lists.debian.org/debian-lts-announce/2019/05/msg00042.html
• https://security.netapp.com/advisory/ntap-20190517-0005/