RHSA-2020:5656 - Security Advisory

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 Moderate. 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: out of bounds write in function i2c_smbus_xfer_emulated in drivers/i2c/i2c-core-smbus.c (CVE-2017-18551)
• kernel: race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c leads to use-after-free (CVE-2018-20836)
• kernel: out of bounds write in i2c driver leads to local escalation of privilege (CVE-2019-9454)
• kernel: Denial Of Service in the __ipmi_bmc_register() function in drivers/char/ipmi/ipmi_msghandler.c (CVE-2019-19046)
• kernel: mounting a crafted ext4 filesystem image, performing some operations, and unmounting can lead to a use-after-free in ext4_put_super in fs/ext4/super.c (CVE-2019-19447)
• kernel: out-of-bounds write via crafted keycode table (CVE-2019-20636)
• kernel: sg_write function lacks an sg_remove_request call in a certain failure case (CVE-2020-12770)

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.

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 Power LE - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux for x86_64 - 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 - 1707796 - CVE-2018-20836 kernel: race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c leads to use-after-free
• BZ - 1757368 - CVE-2017-18551 kernel: out of bounds write in function i2c_smbus_xfer_emulated in drivers/i2c/i2c-core-smbus.c
• BZ - 1774988 - CVE-2019-19046 kernel: Denial Of Service in the __ipmi_bmc_register() function in drivers/char/ipmi/ipmi_msghandler.c
• BZ - 1781679 - CVE-2019-19447 kernel: mounting a crafted ext4 filesystem image, performing some operations, and unmounting can lead to a use-after-free in ext4_put_super in fs/ext4/super.c
• BZ - 1818818 - CVE-2019-9454 kernel: out of bounds write in i2c driver leads to local escalation of privilege
• BZ - 1824059 - CVE-2019-20636 kernel: out-of-bounds write via crafted keycode table
• BZ - 1834845 - CVE-2020-12770 kernel: sg_write function lacks an sg_remove_request call in a certain failure case

CVEs

• CVE-2017-18551
• CVE-2018-20836
• CVE-2019-9454
• CVE-2019-19046
• CVE-2019-19447
• CVE-2019-20636
• CVE-2020-12770

References

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