Important: kernel security, bug fix, and enhancement update

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 7.6 Extended Update Support.

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: Use-after-free in __blk_drain_queue() function in block/blk-core.c (CVE-2018-20856)
  
• kernel: heap overflow in mwifiex_update_vs_ie() function of Marvell WiFi driver (CVE-2019-14816)
  
• kernel: heap-based buffer overflow in mwifiex_process_country_ie() function in drivers/net/wireless/marvell/mwifiex/sta_ioctl.c (CVE-2019-14895)
  
• kernel: buffer overflow in cfg80211_mgd_wext_giwessid in net/wireless/wext-sme.c (CVE-2019-17133)
  

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):

• [PATCH] perf: Fix a race between ring_buffer_detach() and ring_buffer_wakeup() (BZ#1772826)
  
• core: backports from upstream (BZ#1780031)
  
• Race between tty_open() and flush_to_ldisc() using the tty_struct->driver_data field. (BZ#1780160)
  
• [Hyper-V][RHEL7.6]Hyper-V guest waiting indefinitely for RCU callback when removing a mem cgroup (BZ#1783176)
  

Enhancement(s):

• Selective backport: perf: Sync with upstream v4.16 (BZ#1782752)

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 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server (for IBM Power LE) - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Virtualization Host - Extended Update Support 4.2 for RHEL 7.6 x86_64

Fixes

• BZ - 1738705 - CVE-2018-20856 kernel: Use-after-free in __blk_drain_queue() function in block/blk-core.c
• BZ - 1744149 - CVE-2019-14816 kernel: heap overflow in mwifiex_update_vs_ie() function of Marvell WiFi driver
• BZ - 1771909 - CVE-2019-17133 kernel: buffer overflow in cfg80211_mgd_wext_giwessid in net/wireless/wext-sme.c
• BZ - 1774870 - CVE-2019-14895 kernel: heap-based buffer overflow in mwifiex_process_country_ie() function in drivers/net/wireless/marvell/mwifiex/sta_ioctl.c

CVEs

• CVE-2018-20856
• CVE-2019-14816
• CVE-2019-14895
• CVE-2019-17133

References

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