Improper locking in Linux kernel - CVE-2021-4149

Vulnerability identifier: #VU64071

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-4149

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to perform a denial of service attack (DoS) on the target system.

The vulnerability exists in btrfs_alloc_tree_b in fs/btrfs/extent-tree.c in the Linux kernel due to an improper lock operation in btrfs. A local user can exploit this vulnerability to cause a deadlock, resulting in a denial of service condition.

Linux kernel
SUSE Linux Enterprise Micro
Ubuntu
SUSE Linux Enterprise Module for Realtime
SUSE Linux Enterprise Module for Public Cloud
linux-image-aws (Ubuntu package)
linux-image-lowlatency-lts-xenial (Ubuntu package)
linux-image-4.4.0-239-lowlatency (Ubuntu package)
linux-image-4.4.0-239-generic (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-generic-lts-xenial (Ubuntu package)
linux-image-4.4.0-1118-kvm (Ubuntu package)
linux-image-virtual-lts-xenial (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-4.4.0-1155-aws (Ubuntu package)
linux-image-4.4.0-1117-aws (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-virtual-hwe-16.04 (Ubuntu package)
linux-image-generic-hwe-16.04 (Ubuntu package)
linux-image-lowlatency-hwe-16.04 (Ubuntu package)
linux-image-4.15.0-184-generic (Ubuntu package)
linux-image-4.15.0-184-generic-lpae (Ubuntu package)
linux-image-4.15.0-184-lowlatency (Ubuntu package)
linux-image-oracle-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1098-oracle (Ubuntu package)
linux-image-aws-hwe (Ubuntu package)
linux-image-raspi2 (Ubuntu package)
linux-image-4.15.0-1114-raspi2 (Ubuntu package)
linux-image-4.15.0-1119-kvm (Ubuntu package)
linux-image-snapdragon (Ubuntu package)
linux-image-4.15.0-1132-snapdragon (Ubuntu package)
linux-image-aws-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1133-aws (Ubuntu package)
linux-image-azure-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1142-azure (Ubuntu package)
gfs2-kmp-rt-debuginfo
kernel-rt
kernel-rt-debugsource
kernel-rt-devel
kernel-rt-devel-debuginfo
kernel-rt_debug
kernel-rt_debug-debuginfo
kernel-rt_debug-debugsource
kernel-rt_debug-devel
kernel-rt_debug-devel-debuginfo
kernel-syms-rt
ocfs2-kmp-rt
ocfs2-kmp-rt-debuginfo
kernel-devel-rt
kernel-source-rt
kernel-rt-debuginfo
dlm-kmp-rt-debuginfo
dlm-kmp-rt
cluster-md-kmp-rt-debuginfo
cluster-md-kmp-rt
gfs2-kmp-rt
kernel-azure
kernel-source-azure
kernel-devel-azure
kernel-azure-debuginfo
kernel-azure-debugsource
kernel-azure-devel
kernel-azure-devel-debuginfo
kernel-syms-azure
linux-image-oem (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-gke (Ubuntu package)
SCALANCE S615 EEC
SCALANCE MUM856-1 (RoW)
SCALANCE MUM856-1 (EU)
SCALANCE MUM853-1 (EU)
SCALANCE M876-4 (NAM)
SCALANCE M876-4 (EU)
SCALANCE M876-4
SCALANCE M876-3 (ROK)
SCALANCE M876-3 (EVDO)
SCALANCE M874-3
SCALANCE M874-2
SCALANCE M826-2 SHDSL-Router
SCALANCE M816-1 ADSL-Router (Annex B)
SCALANCE M816-1 ADSL-Router (Annex A)
SCALANCE M812-1 ADSL-Router (Annex B)
SCALANCE M812-1 ADSL-Router (Annex A)
SCALANCE M804PB
RUGGEDCOM RM1224 LTE(4G) NAM
RUGGEDCOM RM1224 LTE(4G) EU
SCALANCE S615

Install updates from vendor's website.

Linux kernel - update to 5.15 rc6
linux-image-aws (Ubuntu package) - update to Ubuntu Pro (Infra-only)
linux-image-lowlatency-lts-xenial (Ubuntu package) - update to Ubuntu Pro (Infra-only)
linux-image-4.4.0-239-lowlatency (Ubuntu package) - update to Ubuntu Pro
linux-image-4.4.0-239-generic (Ubuntu package) - update to Ubuntu Pro
linux-image-kvm (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 4.15.0.1119.114
linux-image-generic-lts-xenial (Ubuntu package) - update to Ubuntu Pro (Infra-only)
linux-image-4.4.0-1118-kvm (Ubuntu package) - update to Ubuntu Pro
linux-image-virtual-lts-xenial (Ubuntu package) - update to Ubuntu Pro (Infra-only)
linux-image-lowlatency (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 4.15.0.184.172
linux-image-generic (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 4.15.0.184.172
linux-image-virtual (Ubuntu package) - addressed in versions Ubuntu Pro (Infra-only), 4.15.0.184.172
linux-image-4.4.0-1155-aws (Ubuntu package) - update to Ubuntu Pro
linux-image-4.4.0-1117-aws (Ubuntu package) - update to Ubuntu Pro
linux-image-generic-lpae (Ubuntu package) - update to 4.15.0.184.172
linux-image-virtual-hwe-16.04 (Ubuntu package) - update to 4.15.0.184.172
linux-image-generic-hwe-16.04 (Ubuntu package) - update to 4.15.0.184.172
linux-image-lowlatency-hwe-16.04 (Ubuntu package) - update to 4.15.0.184.172
linux-image-4.15.0-184-generic (Ubuntu package) - update to 4.15.0-184.194
linux-image-4.15.0-184-generic-lpae (Ubuntu package) - update to 4.15.0-184.194
linux-image-4.15.0-184-lowlatency (Ubuntu package) - update to 4.15.0-184.194
linux-image-oracle-lts-18.04 (Ubuntu package) - update to 4.15.0.1098.107
linux-image-4.15.0-1098-oracle (Ubuntu package) - update to 4.15.0-1098.108
linux-image-aws-hwe (Ubuntu package) - update to 4.15.0.1099.92
linux-image-raspi2 (Ubuntu package) - update to 4.15.0.1114.111
linux-image-4.15.0-1114-raspi2 (Ubuntu package) - update to 4.15.0-1114.122
linux-image-4.15.0-1119-kvm (Ubuntu package) - update to 4.15.0-1119.123
linux-image-snapdragon (Ubuntu package) - update to 4.15.0.1132.133
linux-image-4.15.0-1132-snapdragon (Ubuntu package) - update to 4.15.0-1132.142
linux-image-aws-lts-18.04 (Ubuntu package) - update to 4.15.0.1133.135
linux-image-4.15.0-1133-aws (Ubuntu package) - update to 4.15.0-1133.143
linux-image-azure-lts-18.04 (Ubuntu package) - update to 4.15.0.1142.114
linux-image-4.15.0-1142-azure (Ubuntu package) - update to 4.15.0-1142.156
gfs2-kmp-rt-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt-debugsource - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt-devel - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt-devel-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt_debug - update to 5.3.18-68.1
kernel-rt_debug-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt_debug-debugsource - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt_debug-devel - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt_debug-devel-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-syms-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
ocfs2-kmp-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
ocfs2-kmp-rt-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-devel-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-source-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-rt-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
dlm-kmp-rt-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
dlm-kmp-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
cluster-md-kmp-rt-debuginfo - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
cluster-md-kmp-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
gfs2-kmp-rt - addressed in versions 5.3.18-68.1, 5.3.18-150300.71.1
kernel-azure - update to 5.3.18-150300.38.37.1
kernel-source-azure - update to 5.3.18-150300.38.37.1
kernel-devel-azure - update to 5.3.18-150300.38.37.1
kernel-azure-debuginfo - update to 5.3.18-150300.38.37.1
kernel-azure-debugsource - update to 5.3.18-150300.38.37.1
kernel-azure-devel - update to 5.3.18-150300.38.37.1
kernel-azure-devel-debuginfo - update to 5.3.18-150300.38.37.1
kernel-syms-azure - update to 5.3.18-150300.38.37.1
linux-image-oem (Ubuntu package) - update to 5.4.0.117.132~18.04.99
linux-image-oracle (Ubuntu package) - update to 5.4.0.1076.83~18.04.54
linux-image-azure (Ubuntu package) - update to 5.4.0.1083.61
linux-image-gcp (Ubuntu package) - update to 5.13.0.1027.32~20.04.1
linux-image-gke (Ubuntu package) - update to 5.15.0.1005.10
SCALANCE S615 EEC - update to 7.2
SCALANCE S615 - update to 7.2
SCALANCE MUM856-1 (RoW) - update to 7.2
SCALANCE MUM856-1 (EU) - update to 7.2
SCALANCE MUM853-1 (EU) - update to 7.2
SCALANCE M876-4 (NAM) - update to 7.2
SCALANCE M876-4 (EU) - update to 7.2
SCALANCE M876-4 - update to 7.2
SCALANCE M876-3 (ROK) - update to 7.2
SCALANCE M876-3 (EVDO) - update to 7.2
SCALANCE M874-3 - update to 7.2
SCALANCE M874-2 - update to 7.2
SCALANCE M826-2 SHDSL-Router - update to 7.2
SCALANCE M816-1 ADSL-Router (Annex B) - update to 7.2
SCALANCE M816-1 ADSL-Router (Annex A) - update to 7.2
SCALANCE M812-1 ADSL-Router (Annex B) - update to 7.2
SCALANCE M812-1 ADSL-Router (Annex A) - update to 7.2
SCALANCE M804PB - update to 7.2
RUGGEDCOM RM1224 LTE(4G) NAM - update to 7.2
RUGGEDCOM RM1224 LTE(4G) EU - update to 7.2

• https://lkml.org/lkml/2021/9/13/2565
• https://bugzilla.redhat.com/show_bug.cgi?id=2026485
• https://lkml.org/lkml/2021/10/18/885

• Ubuntu update for linux
• Multiple vulnerabilities in Siemens RUGGEDCOM and SCALANCE Products
• SUSE update for the Linux Kernel
• Ubuntu update for linux-aws
• Ubuntu update for linux-aws
• Ubuntu update for linux
• SUSE update for the Linux Kernel
• SUSE update for the Linux Kernel