A flaw was found in systemd. Attacker controlled alloca() in function unitnamepathescape() leads to a crash in systemd and ultimately a kernel panic. Systemd parses the content of /proc/self/mountinfo and each mountpoint is passed to mountsetupunit(), which calls unitnamepathescape() underneath to duplicate the string through alloca(). A local attacker who is able to mount a filesystem on a very long path can crash systemd and the whole system.

Upstream PR: https://github.com/systemd/systemd/pull/20256

Upstream commit: https://github.com/systemd/systemd/pull/20256/commits/441e0115646d54f080e5c3bb0ba477c892861ab9