A denial of service has been found in Linux <= 4.16.9. An attacker can block any read() access to /proc/PID/cmdline by mmap()ing a FUSE file (Filesystem in Userspace) onto this process's command-line arguments. The attacker can therefore block pgrep, pidof, pkill, ps, and w, either forever (a denial of service), or for some controlled time (a synchronization tool for exploiting other vulnerabilities).
A denial of service has been found in Linux <= 4.16.9. An attacker can block any read() access to /proc/PID/cmdline by mmap()ing a FUSE file (Filesystem in Userspace) onto this process's command-line arguments. The attacker can therefore block pgrep, pidof, pkill, ps, and w, either forever (a denial of service), or for some controlled time (a synchronization tool for exploiting other vulnerabilities).
https://www.qualys.com/2018/05/17/procps-ng-audit-report-advisory.txt https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7f7ccc2ccc2e70c6054685f5e3522efa81556830
Fixed in v4.17