LSN-0082-1

Description

Kernel Live Patch Security Notice Jann Horn discovered that the tty subsystem of the Linux kernel did not use consistent locking in some situations, leading to a read-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly expose sensitive information (kernel memory).(CVE-2020-29660) Jann Horn discovered a race condition in the tty subsystem of the Linux kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after- free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code.(CVE-2020-29661) De4dCr0w of 360 Alpha Lab discovered that the BPF verifier in the Linux kernel did not properly handle mod32 destination register truncation when the source register was known to be 0. A local attacker could use this to expose sensitive information (kernel memory) or possibly execute arbitrary code.(CVE-2021-3444) kernel: use-after-free in route4_change() in net/sched/cls_route.c(CVE-2021-3715)

Affected Systems

• ubuntu•linux

  all | < 4.4.0-203.235 | < 4.15.0-136.140 | < 5.4.0-70.78

• ubuntu•linux-gcp

  all | < 5.4.0-1040.43

• ubuntu•linux-gke

  all | < 5.4.0-1039.41

• ubuntu•linux-gke-4.15

  all | < 4.15.0-1079.84

• ubuntu•linux-gke-5.4

  all | < 5.4.0-1039.41~18.04.1

• ubuntu•linux-gkeop

  all | < 5.4.0-1012.13

• ubuntu•linux-gkeop-5.4

  all | < 5.4.0-1012.13~18.04.1

• ubuntu•linux-hwe

  all | < 4.15.0-136.140~16.04.1

• ubuntu•linux-hwe-5.4

  all | < 5.4.0-70.78~18.04.1

• ubuntu•linux-oem

  all

References (5)

• https://ubuntu.com/security/notices/LSN-0082-1
• https://ubuntu.com/security/CVE-2020-29660
• https://ubuntu.com/security/CVE-2020-29661
• https://ubuntu.com/security/CVE-2021-3444
• https://ubuntu.com/security/CVE-2021-3715