RHSA-2021:1070 - 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: out-of-bounds read in libiscsi module (CVE-2021-27364)
• kernel: heap buffer overflow in the iSCSI subsystem (CVE-2021-27365)
• kernel: iscsi: unrestricted access to sessions and handles (CVE-2021-27363)

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):

• RHEL7.9 Realtime crashes due to a blocked task detection. The blocked task is stuck in unregister_shrinker() where multiple tasks have taken the shrinker_rwsem and are fighting on a dentry's d_lockref lock rt_mutex. [kernel-rt] (BZ#1935557)
• kernel-rt: update to the latest RHEL7.9.z5 source tree (BZ#1939220)

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 - 1930078 - CVE-2021-27365 kernel: heap buffer overflow in the iSCSI subsystem
• BZ - 1930079 - CVE-2021-27363 kernel: iscsi: unrestricted access to sessions and handles
• BZ - 1930080 - CVE-2021-27364 kernel: out-of-bounds read in libiscsi module

CVEs

• CVE-2021-27363
• CVE-2021-27364
• CVE-2021-27365

References

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