CVE-2019-19227

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.

Weakness

A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.

Affected Software

Potential Mitigations

References

• http://lists.opensuse.org/opensuse-security-announce/2019-12/msg00029.html
• http://packetstormsecurity.com/files/155890/Slackware-Security-Advisory-Slackware-14.2-kernel-Updates.html
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.1
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9804501fa1228048857910a6bf23e085aade37cc
• https://lists.debian.org/debian-lts-announce/2020/01/msg00013.html
• https://lists.debian.org/debian-lts-announce/2020/03/msg00001.html
• https://seclists.org/bugtraq/2020/Jan/10
• https://security.netapp.com/advisory/ntap-20200103-0001/
• https://usn.ubuntu.com/4254-1/
• https://usn.ubuntu.com/4254-2/
• https://usn.ubuntu.com/4258-1/
• https://usn.ubuntu.com/4287-1/
• https://usn.ubuntu.com/4287-2/