7.5 - RHSA-2020:0664

Problem Description:

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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux ComputeNode EUS (v. 7.6) - noarch, x86_64 Red Hat Enterprise Linux ComputeNode Optional EUS (v. 7.6) - x86_64 Red Hat Enterprise Linux Server EUS (v. 7.6) - noarch, ppc64, ppc64le, s390x, x86_64 Red Hat Enterprise Linux Server Optional EUS (v. 7.6) - ppc64, ppc64le, x86_64

3. 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)

4. 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.

5. Bugs fixed (https://bugzilla.redhat.com/):

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