In the AppleTalk subsystem in the Linux kernel before 5.1, there is a potential NULL pointer dereference because register_snap_client may return NULL. This will lead to denial of service in net/appletalk/aarp.c and net/appletalk/ddp.c, as demonstrated by unregister_snap_client, aka CID-9804501fa122. CREATE(Triage):(User=admin) [CVE-2019-19227|https://nvd.nist.gov/vuln/detail/CVE-2019-19227]
