CVE-2019-20794

Name	CVE-2019-20794
Description	An issue was discovered in the Linux kernel 4.18 through 5.6.11 when unprivileged user namespaces are allowed. A user can create their own PID namespace, and mount a FUSE filesystem. Upon interaction with this FUSE filesystem, if the userspace component is terminated via a kill of the PID namespace's pid 1, it will result in a hung task, and resources being permanently locked up until system reboot. This can result in resource exhaustion.
Source	CVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
linux (PTS)	buster, buster (security)	4.19.249-2	vulnerable
	bullseye	5.10.140-1	vulnerable
	bullseye (security)	5.10.136-1	vulnerable
	bookworm	5.19.6-1	vulnerable
	sid	5.19.11-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
linux	source	(unstable)	(unfixed)

Notes

[bullseye] - linux <postponed> (Minor issue, revisit when fixed upstream)
[buster] - linux <postponed> (Minor issue, revisit when fixed upstream)
https://sourceforge.net/p/fuse/mailman/message/36598753/