Advisories ยป MGASA-2021-0204

Updated kernel packages fix security vulnerabilities

Publication date: 02 May 2021
Type: security
Affected Mageia releases : 7 , 8
CVE: CVE-2021-23133 , CVE-2021-29155


This kernel update is based on upstream 5.10.33 and fixes at least the
following security issues:

A race condition in Linux kernel SCTP sockets (net/sctp/socket.c) before
5.12-rc8 can lead to kernel privilege escalation from the context of a
network service or an unprivileged process. If sctp_destroy_sock is called
without sock_net(sk)->sctp.addr_wq_lock then an element is removed from
the auto_asconf_splist list without any proper locking. This can be
exploited by an attacker with network service privileges to escalate to
root or from the context of an unprivileged user directly if a
BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some
SCTP socket (CVE-2021-23133).

An issue was discovered in the Linux kernel through 5.11.x. kernel/bpf/
verifier.c performs undesirable out-of-bounds speculation on pointer
arithmetic, leading to side-channel attacks that defeat Spectre mitigations
and obtain sensitive information from kernel memory. Specifically, for
sequences of pointer arithmetic operations, the pointer modification
performed by the first operation is not correctly accounted for when
restricting subsequent operations (CVE-2021-29155).

This update also contains the following:
- xtables-addons has been updated to 3.18 (only in Mageia 8)
- wireguard-tools has been updated to v1.0.20210424-1.mga8

For other upstream fixes, see the referenced changelogs.