Synopsis

Important: kernel security, bug fix, and enhancement update

Type/Severity

Security Advisory: Important

Topic

An update for kernel is now available for Red Hat Enterprise Linux 8.

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: locking issue in drivers/tty/tty_jobctrl.c can lead to an use-after-free (CVE-2020-29661)
• kernel: performance counters race condition use-after-free (CVE-2020-14351)
• kernel: ICMP rate limiting can be used for DNS poisoning attack (CVE-2020-25705)

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):

• Final fixes + drop alpha_support flag requirement for Tigerlake (BZ#1882620)
• OVS complains Invalid Argument on TCP packets going into conntrack (BZ#1892744)
• BUG: using smp_processor_id() in preemptible [00000000] code: handler106/3082 (BZ#1893281)
• Icelake performance - add intel_idle: Customize IceLake server support to RHEL-8 (BZ#1897183)
• [mlx5] IPV6 TOS rewrite flows are not getting offloaded in HW (BZ#1897688)
• RHEL 8.3 SAS - multipathd fails to re-establish paths during controller random reset (BZ#1900112)
• RHEL8.3 Beta - RHEL8.3 hangs on dbginfo.sh execution, crash dump generated (mm-) (BZ#1903019)
• Win10 guest automatic reboot after migration in Win10 and WSL2 on AMD hosts (BZ#1905084)
• block, dm: fix IO splitting for stacked devices (BZ#1905136)
• Failed to hotplug scsi-hd disks (BZ#1905214)
• PCI quirk needed to prevent GPU hang (BZ#1906516)
• RHEL8.2 - various patches to stabilize the OPAL error log processing and the powernv dump processing (ESS) (BZ#1907301)
• pmtu not working with tunnels as bridge ports and br_netfilter loaded (BZ#1907576)
• [ThinkPad X13/T14/T14s AMD]: Kdump failed (BZ#1907775)
• NFSv4 client improperly handles interrupted slots (BZ#1908312)
• NFSv4.1 client ignores ERR_DELAY during LOCK recovery, could lead to data corruption (BZ#1908313)
• [Regression] RHEL8.2 - [kernel 148.el8] cpu (sys) time regression in SAP HANA 2.0 benchmark benchInsertSubSelectPerformance (BZ#1908519)
• RHEL8: kernel-rt: kernel BUG at kernel/sched/deadline.c:1462! (BZ#1908731)
• SEV VM hang at efi_mokvar_sysfs_init+0xa9/0x19d during boot (BZ#1909243)
• C6gn support requires "Ensure dirty bit is preserved across pte_wrprotect" patch (BZ#1909577)
• [Lenovo 8.3 & 8.4 Bug] [Regression] No response from keyboard and mouse when boot from tboot kernel (BZ#1911555)
• Kernel crash with krb5p (BZ#1912478)
• [RHEL8] Need additional backports for FIPS 800-90A DRBG entropy seeding source (BZ#1912872)
• [Hyper-V][RHEL-8] Request to included a commit that adds a timeout to vmbus_wait_for_unload (BZ#1913528)
• Host becomes unresponsive during stress-ng --cyclic test rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (BZ#1913964)
• RHEL8.4: Backport upstream RCU patches up to v5.6 (BZ#1915638)
• Missing mm backport to fix regression introduced by another mm backport (BZ#1915814)
• [Hyper-V][RHEL-8]video: hyperv_fb: Fix the cache type when mapping the VRAM Edit (BZ#1917711)
• ionic 0000:39:00.0 ens2: IONIC_CMD_Q_INIT (40) failed: IONIC_RC_ERROR (-5) (BZ#1918372)
• [certification] mlx5_core depends on tls triggering TAINT_TECH_PREVIEW even if no ConnectX-6 card is present (BZ#1918743)
• kvm-rhel8.3 [AMD] - system crash observed while powering on virtual machine with attached VF interfaces. (BZ#1919885)

Enhancement(s):

• [Mellanox 8.4 FEAT] mlx5: Add messages when VF-LAG fails to start (BZ#1892344)

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 for x86_64 8 x86_64
• Red Hat Enterprise Linux for IBM z Systems 8 s390x
• Red Hat Enterprise Linux for Power, little endian 8 ppc64le
• Red Hat Enterprise Linux for ARM 64 8 aarch64
• Red Hat CodeReady Linux Builder for x86_64 8 x86_64
• Red Hat CodeReady Linux Builder for Power, little endian 8 ppc64le
• Red Hat CodeReady Linux Builder for ARM 64 8 aarch64

Fixes

• BZ - 1862849 - CVE-2020-14351 kernel: performance counters race condition use-after-free
• BZ - 1894579 - CVE-2020-25705 kernel: ICMP rate limiting can be used for DNS poisoning attack
• BZ - 1906525 - CVE-2020-29661 kernel: locking issue in drivers/tty/tty_jobctrl.c can lead to an use-after-free

CVEs

• CVE-2020-14351
• CVE-2020-25705
• CVE-2020-29661

References