RHSA-2021:3327 - Security Advisory

Topic

An update for kernel is now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

The kernel packages contain the Linux kernel, the core of any Linux operating system.

Security Fix(es):

• kernel: out-of-bounds write in xt_compat_target_from_user() in net/netfilter/x_tables.c (CVE-2021-22555)
• kernel: race condition for removal of the HCI controller (CVE-2021-32399)
• kernel: powerpc: RTAS calls can be used to compromise kernel integrity (CVE-2020-27777)
• kernel: Local privilege escalation due to incorrect BPF JIT branch displacement computation (CVE-2021-29154)
• kernel: lack a full memory barrier upon the assignment of a new table value in net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h may lead to DoS (CVE-2021-29650)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Bug Fix(es):

• SAN Switch rebooted and caused (?) OpenStack compute node to reboot (BZ#1897576)
• sysfs: cannot create duplicate filename '/class/mdio_bus/ixgbe-8100 (BZ#1915449)
• XFS: read-only recovery does not update free space accounting in superblock (BZ#1921551)
• The memcg_params field of kmem_cache struct contains an old slab address that is to small for the current size of memcg_limited_groups_array_size. (BZ#1951810)
• Backport of upstream patch "net: Update window_clamp if SOCK_RCVBUF is set " into rhel-7 (BZ#1962196)
• Kernel panic in init_cq_frag_buf (BZ#1962499)
• futex: futex_requeue can potentially free the pi_state structure twice (BZ#1966856)
• be_poll lockup doing ifenslave when netconsole using bond (BZ#1971744)
• OCP4.7 nodes panic at BUG_ON in nf_nat_setup_info() (BZ#1972970)

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

The system must be rebooted for this update to take effect.

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Virtualization Host 4 for RHEL 7 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 1897576 - SAN Switch rebooted and caused (?) OpenStack compute node to reboot
• BZ - 1900844 - CVE-2020-27777 kernel: powerpc: RTAS calls can be used to compromise kernel integrity
• BZ - 1945388 - CVE-2021-29650 kernel: lack a full memory barrier upon the assignment of a new table value in net/netfilter/x_tables.c and include/linux/netfilter/x_tables.h may lead to DoS
• BZ - 1946684 - CVE-2021-29154 kernel: Local privilege escalation due to incorrect BPF JIT branch displacement computation
• BZ - 1970807 - CVE-2021-32399 kernel: race condition for removal of the HCI controller
• BZ - 1980101 - CVE-2021-22555 kernel: out-of-bounds write in xt_compat_target_from_user() in net/netfilter/x_tables.c

CVEs

• CVE-2020-27777
• CVE-2021-22555
• CVE-2021-29154
• CVE-2021-29650
• CVE-2021-32399

References

• https://access.redhat.com/security/updates/classification/#important