RHSA-2021:2726 - Security Advisory

Topic

An update for kernel-rt 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-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.

Security Fix(es):

• kernel: size_t-to-int conversion vulnerability in the filesystem layer (CVE-2021-33909)
• kernel: use-after-free in net/bluetooth/hci_event.c when destroying an hci_chan (CVE-2021-33034)
• kernel: use-after-free in show_numa_stats function (CVE-2019-20934)
• kernel: mishandles invalid descriptors in drivers/media/usb/gspca/xirlink_cit.c (CVE-2020-11668)
• kernel: use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c (CVE-2021-33033)

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):

• kernel-rt: update to the latest RHEL7.9.z7 source tree (BZ#1967333)

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 Real Time 7 x86_64
• Red Hat Enterprise Linux for Real Time for NFV 7 x86_64

Fixes

• BZ - 1824792 - CVE-2020-11668 kernel: mishandles invalid descriptors in drivers/media/usb/gspca/xirlink_cit.c
• BZ - 1902788 - CVE-2019-20934 kernel: use-after-free in show_numa_stats function
• BZ - 1961300 - CVE-2021-33033 kernel: use-after-free in cipso_v4_genopt in net/ipv4/cipso_ipv4.c
• BZ - 1961305 - CVE-2021-33034 kernel: use-after-free in net/bluetooth/hci_event.c when destroying an hci_chan
• BZ - 1970273 - CVE-2021-33909 kernel: size_t-to-int conversion vulnerability in the filesystem layer

CVEs

• CVE-2019-20934
• CVE-2020-11668
• CVE-2021-33033
• CVE-2021-33034
• CVE-2021-33909

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/security/vulnerabilities/RHSB-2021-006