An issue was discovered in sd-bus in systemd 239. bus_process_object() in libsystemd/sd-bus/bus-objects.c allocates a variable-length stack buffer for temporarily storing the object path of incoming D-Bus messages. An unprivileged local user can exploit this by sending a specially crafted message to PID1, causing the stack pointer to jump over the stack guard pages into an unmapped memory region and trigger a denial of service (systemd PID1 crash and kernel panic).
lists.opensuse.org/opensuse-security-announce/2019-02/msg00070.html
lists.opensuse.org/opensuse-security-announce/2019-05/msg00062.html
www.openwall.com/lists/oss-security/2019/02/18/3
www.openwall.com/lists/oss-security/2019/02/19/1
www.openwall.com/lists/oss-security/2021/07/20/2
www.securityfocus.com/bid/107081
access.redhat.com/errata/RHSA-2019:0368
access.redhat.com/errata/RHSA-2019:0990
access.redhat.com/errata/RHSA-2019:1322
access.redhat.com/errata/RHSA-2019:1502
access.redhat.com/errata/RHSA-2019:2805
github.com/systemd/systemd/commits/master/src/libsystemd/sd-bus/bus-objects.c
kc.mcafee.com/corporate/index?page=content&id=SB10278
lists.debian.org/debian-lts-announce/2019/02/msg00031.html
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/N67IOBOTDOMVNQJ5QRU2MXLEECXPGNVJ/
security.netapp.com/advisory/ntap-20190327-0004/
usn.ubuntu.com/3891-1/
www.debian.org/security/2019/dsa-4393