Paul Mackerras

The issue is related to the function `dumpppp` of the file `pppdump/pppdump.c` of the component `pppdump`. It involves improper validation of array index due to the manipulation of the argument `spkt.buf`/`rpkt.buf`. This could potentially allow a remote attacker to access confidential data, compromise its integrity, and cause a denial of service. The real existence of this vulnerability is still doubted at the moment.

The issue is caused by a conflicting use of HSTATE HOST R1 to store r1 state in kvmppc hv entry plus in kvmppc {save,restore} tm, leading to a stack corruption. An attacker with the ability to run code in kernel space of a guest VM can cause the host kernel to panic. The vulnerability was introduced by two commits that landed in versions 4.8 and 4.17.

The issue allows local users to cause a denial of service, resulting in a system crash due to a NULL pointer dereference. This can be achieved by making a KVM CHECK EXTENSION KVM CAP PPC HTM ioctl call to the `/dev/kvm` API endpoint.

The issue allows guest OS users to cause a denial of service, resulting in a host OS infinite loop. This occurs when a H CEDE hypercall is made during the existence of a suspended transaction, affecting PowerPC platforms with CONFIG KVM BOOK3S 64 HV enabled.

The issue concerns multiple vulnerabilities in various packages of the openSUSE operating system, which can lead to a breach of confidentiality, integrity, and availability of protected information. These vulnerabilities can be exploited remotely.