Race condition in Linux kernel - CVE-2018-20836

Vulnerability identifier: #VU31080

CSH Severity: High

CVSS v4: 9.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2018-20836

CWE-ID: CWE-362

Exploitation vector: Remote access

Exploit availability: No public exploit available

The vulnerability allows a remote non-authenticated attacker to execute arbitrary code.

An issue was discovered in the Linux kernel before 4.20. There is a race condition in smp_task_timedout() and smp_task_done() in drivers/scsi/libsas/sas_expander.c, leading to a use-after-free.

Linux kernel
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux Workstation
Red Hat Virtualization Host - Extended Update Support 4.2 for RHEL
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux EUS Compute Node
Red Hat Enterprise Linux for Power, big endian - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Opensuse
kernel (Red Hat package)
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
kernel-rt (Red Hat package)
EMC ECS

Install update from vendor's website.

Linux kernel - update to 4.2
kernel (Red Hat package) - addressed in versions 3.10.0-957.65.1.el7, 3.10.0-1062.43.1.el7, 3.10.0-1160.el7
EMC ECS - update to 3.5.0.1
kernel-rt (Red Hat package) - update to 3.10.0-1160.rt56.1131.el7

• http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00014.html
• http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00025.html
• http://www.securityfocus.com/bid/108196
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b90cd6f2b905905fb42671009dc0e27c310a16ae
• https://github.com/torvalds/linux/commit/b90cd6f2b905905fb42671009dc0e27c310a16ae
• https://lists.debian.org/debian-lts-announce/2019/08/msg00016.html
• https://lists.debian.org/debian-lts-announce/2019/08/msg00017.html
• https://seclists.org/bugtraq/2019/Aug/13
• https://seclists.org/bugtraq/2019/Aug/18
• https://security.netapp.com/advisory/ntap-20190719-0003/
• https://support.f5.com/csp/article/K11225249
• https://usn.ubuntu.com/4076-1/
• https://www.debian.org/security/2019/dsa-4495
• https://www.debian.org/security/2019/dsa-4497

• Race condition in Linux kernel
• OpenSUSE Linux update for the Linux Kernel
• OpenSUSE Linux update for the Linux Kernel
• Red Hat Enterprise Linux 7.6 update for kernel
• Red Hat Enterprise Linux 7 update for kernel
• Multiple vulnerabilities in Dell EMC ECS
• Red Hat Enterprise Linux 7 update for kernel-rt
• Red Hat Enterprise Linux 7 update for kernel