LSN-0083-1: Kernel Live Patch Security Notice

LSN-0083-1: Kernel Live Patch Security Notice

The BPF subsystem in the Linux kernel before 4.17 mishandles
situations with a long jump over an instruction sequence where inner
instructions require substantial expansions into multiple BPF instructions,
leading to an overflow. This affects kernel/bpf/core.c and
net/core/filter.c.(CVE-2018-25020)

Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host’s physical memory.(CVE-2021-3653)

Nadav Amit discovered that the hugetlb implementation in the Linux kernel
did not perform TLB flushes under certain conditions. A local attacker
could use this to leak or alter data from other processes that use huge
pages.(CVE-2021-4002)

Andy Nguyen discovered that the netfilter subsystem in the Linux kernel
contained an out-of-bounds write in its setsockopt() implementation. A
local attacker could use this to cause a denial of service (system crash)
or possibly execute arbitrary code.(CVE-2021-22555)

It was discovered that the virtual file system implementation in the Linux
kernel contained an unsigned to signed integer conversion error. A local
attacker could use this to cause a denial of service (system crash) or
execute arbitrary code.(CVE-2021-33909)
Source: LSN-0083-1: Kernel Live Patch Security Notice