NULL pointer dereference in Xen - CVE-2020-27675

Vulnerability identifier: #VU83584

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-2020-27675

CWE-ID: CWE-476

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to a NULL pointer dereference error in drivers/xen/events/events_base.c. A malicious guest can trigger a dom0 crash by sending events for a paravirtualized device while simultaneously performing its reconfiguration.

Xen
Amazon Linux AMI
Gentoo Linux
Ubuntu
openEuler
Fedora
linux-image-generic-lpae-lts-xenial (Ubuntu package)
linux-image-virtual-lts-xenial (Ubuntu package)
linux-image-powerpc64-smp-lts-xenial (Ubuntu package)
linux-image-powerpc64-emb-lts-xenial (Ubuntu package)
linux-image-powerpc-smp-lts-xenial (Ubuntu package)
linux-image-generic-lts-xenial (Ubuntu package)
linux-image-lowlatency-lts-xenial (Ubuntu package)
linux-image-powerpc-e500mc-lts-xenial (Ubuntu package)
linux-image-powerpc-smp (Ubuntu package)
linux-image-powerpc64-emb (Ubuntu package)
linux-image-powerpc64-smp (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-powerpc-e500mc (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-4.4.0-198-powerpc-e500mc (Ubuntu package)
linux-image-4.4.0-198-generic (Ubuntu package)
linux-image-4.4.0-198-generic-lpae (Ubuntu package)
linux-image-4.4.0-198-lowlatency (Ubuntu package)
linux-image-4.4.0-198-powerpc-smp (Ubuntu package)
linux-image-4.4.0-198-powerpc64-emb (Ubuntu package)
linux-image-4.4.0-198-powerpc64-smp (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-4.4.0-1083-aws (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-4.4.0-1085-kvm (Ubuntu package)
linux-image-4.4.0-1119-aws (Ubuntu package)
linux-image-raspi2 (Ubuntu package)
linux-image-4.4.0-1143-raspi2 (Ubuntu package)
linux-image-snapdragon (Ubuntu package)
linux-image-4.4.0-1147-snapdragon (Ubuntu package)
app-emulation/xen
app-emulation/xen-tools
kernel
linux-image-generic-lpae-hwe-16.04 (Ubuntu package)
linux-image-virtual-hwe-16.04 (Ubuntu package)
linux-image-oem (Ubuntu package)
linux-image-lowlatency-hwe-16.04 (Ubuntu package)
linux-image-generic-hwe-16.04 (Ubuntu package)
linux-image-4.15.0-129-lowlatency (Ubuntu package)
linux-image-4.15.0-129-generic-lpae (Ubuntu package)
linux-image-4.15.0-129-generic (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-4.15.0-1062-oracle (Ubuntu package)
linux-image-oracle-lts-18.04 (Ubuntu package)
linux-image-gke-4.15 (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-4.15.0-1077-gke (Ubuntu package)
linux-image-4.15.0-1077-raspi2 (Ubuntu package)
linux-image-4.15.0-1082-kvm (Ubuntu package)
linux-image-aws-hwe (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-aws-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1091-aws (Ubuntu package)
linux-image-4.15.0-1091-gcp (Ubuntu package)
linux-image-gcp-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1094-snapdragon (Ubuntu package)
linux-image-azure-lts-18.04 (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-4.15.0-1103-azure (Ubuntu package)
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
perf-debuginfo
kernel-devel
kernel-source
kernel-tools
kernel-tools-debuginfo
kernel-tools-devel
perf
python2-perf
python2-perf-debuginfo
python3-perf
python3-perf-debuginfo
linux-image-oem-osp1 (Ubuntu package)
linux-image-5.4.0-59-generic-lpae (Ubuntu package)
linux-image-5.4.0-59-generic (Ubuntu package)
linux-image-5.4.0-59-lowlatency (Ubuntu package)
linux-image-virtual-hwe-18.04 (Ubuntu package)
linux-image-snapdragon-hwe-18.04 (Ubuntu package)
linux-image-lowlatency-hwe-18.04 (Ubuntu package)
linux-image-generic-hwe-18.04 (Ubuntu package)
linux-image-generic-lpae-hwe-18.04 (Ubuntu package)
linux-image-5.4.0-1026-raspi (Ubuntu package)
linux-image-raspi-hwe-18.04 (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-5.4.0-1031-kvm (Ubuntu package)
linux-image-5.4.0-1033-gcp (Ubuntu package)
linux-image-5.4.0-1033-gke (Ubuntu package)
linux-image-gke-5.4 (Ubuntu package)
linux-image-5.4.0-1034-aws (Ubuntu package)
linux-image-5.4.0-1034-oracle (Ubuntu package)
linux-image-5.4.0-1035-azure (Ubuntu package)
linux-image-generic-64k (Ubuntu package)
linux-image-oem-20.04 (Ubuntu package)
linux-image-5.8.0-44-generic-64k (Ubuntu package)
linux-image-5.8.0-44-lowlatency (Ubuntu package)
linux-image-5.8.0-44-generic (Ubuntu package)
linux-image-5.8.0-44-generic-lpae (Ubuntu package)
linux-image-generic-64k-hwe-20.04 (Ubuntu package)
linux-image-virtual-hwe-20.04 (Ubuntu package)
linux-image-lowlatency-hwe-20.04 (Ubuntu package)
linux-image-generic-lpae-hwe-20.04 (Ubuntu package)
linux-image-generic-hwe-20.04 (Ubuntu package)
linux-image-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1016-raspi (Ubuntu package)
linux-image-5.8.0-1016-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1019-kvm (Ubuntu package)
linux-image-5.8.0-1021-oracle (Ubuntu package)
linux-image-5.8.0-1023-gcp (Ubuntu package)
linux-image-5.8.0-1023-azure (Ubuntu package)
linux-image-5.8.0-1024-aws (Ubuntu package)

Install update from vendor's website.

linux-image-generic-lpae-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-virtual-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-powerpc64-smp-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-powerpc64-emb-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-powerpc-smp-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-generic-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-lowlatency-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-powerpc-e500mc-lts-xenial (Ubuntu package) - update to 4.4.0.198.173
linux-image-powerpc-smp (Ubuntu package) - update to 4.4.0.198.204
linux-image-powerpc64-emb (Ubuntu package) - update to 4.4.0.198.204
linux-image-powerpc64-smp (Ubuntu package) - update to 4.4.0.198.204
linux-image-virtual (Ubuntu package) - addressed in versions 4.4.0.198.204, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-generic (Ubuntu package) - addressed in versions 4.4.0.198.204, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-generic-lpae (Ubuntu package) - addressed in versions 4.4.0.198.204, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-powerpc-e500mc (Ubuntu package) - update to 4.4.0.198.204
linux-image-lowlatency (Ubuntu package) - addressed in versions 4.4.0.198.204, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-4.4.0-198-powerpc-e500mc (Ubuntu package) - update to 4.4.0-198.230~14.04.1
linux-image-4.4.0-198-generic (Ubuntu package) - update to 4.4.0-198.230~14.04.1
linux-image-4.4.0-198-generic-lpae (Ubuntu package) - update to 4.4.0-198.230~14.04.1
linux-image-4.4.0-198-lowlatency (Ubuntu package) - update to 4.4.0-198.230~14.04.1
linux-image-4.4.0-198-powerpc-smp (Ubuntu package) - update to 4.4.0-198.230~14.04.1
linux-image-4.4.0-198-powerpc64-emb (Ubuntu package) - update to 4.4.0-198.230~14.04.1
linux-image-4.4.0-198-powerpc64-smp (Ubuntu package) - update to 4.4.0-198.230~14.04.1
linux-image-aws (Ubuntu package) - addressed in versions 4.4.0.1083.80, 4.4.0.1119.124, 5.4.0.1034.19, 5.4.0.1034.35, 5.8.0.1024.26
linux-image-4.4.0-1083-aws (Ubuntu package) - update to 4.4.0-1083.87
linux-image-kvm (Ubuntu package) - addressed in versions 4.4.0.1085.83, 4.15.0.1082.78, 5.4.0.1031.29, 5.8.0.1019.21
linux-image-4.4.0-1085-kvm (Ubuntu package) - update to 4.4.0-1085.94
linux-image-4.4.0-1119-aws (Ubuntu package) - update to 4.4.0-1119.133
linux-image-raspi2 (Ubuntu package) - addressed in versions 4.4.0.1143.143, 4.15.0.1077.74, 5.4.0.1026.61
linux-image-4.4.0-1143-raspi2 (Ubuntu package) - update to 4.4.0-1143.153
linux-image-snapdragon (Ubuntu package) - addressed in versions 4.4.0.1147.139, 4.15.0.1094.97
linux-image-4.4.0-1147-snapdragon (Ubuntu package) - update to 4.4.0-1147.157
app-emulation/xen - update to 4.13.2
app-emulation/xen-tools - update to 4.13.2
kernel - update to 4.14.209-117.337
linux-image-generic-lpae-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-virtual-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-oem (Ubuntu package) - addressed in versions 4.15.0.129.128, 5.4.0.59.62, 5.4.0.59.65~18.04.54
linux-image-lowlatency-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-generic-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-4.15.0-129-lowlatency (Ubuntu package) - update to 4.15.0-129.132~16.04.1
linux-image-4.15.0-129-generic-lpae (Ubuntu package) - update to 4.15.0-129.132~16.04.1
linux-image-4.15.0-129-generic (Ubuntu package) - update to 4.15.0-129.132~16.04.1
linux-image-oracle (Ubuntu package) - addressed in versions 4.15.0.1062.51, 5.4.0.1034.31, 5.4.0.1034.36~18.04.18, 5.8.0.1021.20
linux-image-4.15.0-1062-oracle (Ubuntu package) - update to 4.15.0-1062.68~16.04.1
linux-image-oracle-lts-18.04 (Ubuntu package) - update to 4.15.0.1062.72
linux-image-gke-4.15 (Ubuntu package) - update to 4.15.0.1077.81
linux-image-gke (Ubuntu package) - addressed in versions 4.15.0.1077.81, 4.15.0.1091.92, 5.8.0.1023.23
linux-image-4.15.0-1077-gke (Ubuntu package) - update to 4.15.0-1077.82
linux-image-4.15.0-1077-raspi2 (Ubuntu package) - update to 4.15.0-1077.82
linux-image-4.15.0-1082-kvm (Ubuntu package) - update to 4.15.0-1082.84
linux-image-aws-hwe (Ubuntu package) - update to 4.15.0.1091.85
linux-image-gcp (Ubuntu package) - addressed in versions 4.15.0.1091.92, 5.4.0.1033.21, 5.4.0.1033.42, 5.8.0.1023.23
linux-image-aws-lts-18.04 (Ubuntu package) - update to 4.15.0.1091.93
linux-image-4.15.0-1091-aws (Ubuntu package) - update to 4.15.0-1091.96~16.04.1
linux-image-4.15.0-1091-gcp (Ubuntu package) - update to 4.15.0-1091.104~16.04.1
linux-image-gcp-lts-18.04 (Ubuntu package) - update to 4.15.0.1091.109
linux-image-4.15.0-1094-snapdragon (Ubuntu package) - update to 4.15.0-1094.103
linux-image-azure-lts-18.04 (Ubuntu package) - update to 4.15.0.1103.76
linux-image-azure (Ubuntu package) - addressed in versions 4.15.0.1103.78, 4.15.0.1103.96, 5.4.0.1035.17, 5.4.0.1035.33, 5.8.0.1023.23
linux-image-4.15.0-1103-azure (Ubuntu package) - addressed in versions 4.15.0-1103.114~14.04.1, 4.15.0-1103.114~16.04.1
kernel - update to 4.19.90-2101.1.0.0055
bpftool - update to 4.19.90-2101.1.0.0055
bpftool-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-debugsource - update to 4.19.90-2101.1.0.0055
perf-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-devel - update to 4.19.90-2101.1.0.0055
kernel-source - update to 4.19.90-2101.1.0.0055
kernel-tools - update to 4.19.90-2101.1.0.0055
kernel-tools-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-tools-devel - update to 4.19.90-2101.1.0.0055
perf - update to 4.19.90-2101.1.0.0055
python2-perf - update to 4.19.90-2101.1.0.0055
python2-perf-debuginfo - update to 4.19.90-2101.1.0.0055
python3-perf - update to 4.19.90-2101.1.0.0055
python3-perf-debuginfo - update to 4.19.90-2101.1.0.0055
linux-image-oem-osp1 (Ubuntu package) - addressed in versions 5.4.0.59.62, 5.4.0.59.65~18.04.54
linux-image-5.4.0-59-generic-lpae (Ubuntu package) - addressed in versions 5.4.0-59.65, 5.4.0-59.65~18.04.1
linux-image-5.4.0-59-generic (Ubuntu package) - addressed in versions 5.4.0-59.65, 5.4.0-59.65~18.04.1
linux-image-5.4.0-59-lowlatency (Ubuntu package) - addressed in versions 5.4.0-59.65, 5.4.0-59.65~18.04.1
linux-image-virtual-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-snapdragon-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-lowlatency-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-generic-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-generic-lpae-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-5.4.0-1026-raspi (Ubuntu package) - addressed in versions 5.4.0-1026.29, 5.4.0-1026.29~18.04.1
linux-image-raspi-hwe-18.04 (Ubuntu package) - update to 5.4.0.1026.30
linux-image-raspi (Ubuntu package) - addressed in versions 5.4.0.1026.61, 5.8.0.1016.19
linux-image-5.4.0-1031-kvm (Ubuntu package) - update to 5.4.0-1031.32
linux-image-5.4.0-1033-gcp (Ubuntu package) - addressed in versions 5.4.0-1033.35, 5.4.0-1033.35~18.04.1
linux-image-5.4.0-1033-gke (Ubuntu package) - update to 5.4.0-1033.35~18.04.1
linux-image-gke-5.4 (Ubuntu package) - update to 5.4.0.1033.35~18.04.2
linux-image-5.4.0-1034-aws (Ubuntu package) - addressed in versions 5.4.0-1034.35, 5.4.0-1034.35~18.04.1
linux-image-5.4.0-1034-oracle (Ubuntu package) - addressed in versions 5.4.0-1034.36, 5.4.0-1034.36~18.04.1
linux-image-5.4.0-1035-azure (Ubuntu package) - addressed in versions 5.4.0-1035.36, 5.4.0-1035.36~18.04.1
linux-image-generic-64k (Ubuntu package) - update to 5.8.0.44.49
linux-image-oem-20.04 (Ubuntu package) - update to 5.8.0.44.49
linux-image-5.8.0-44-generic-64k (Ubuntu package) - update to 5.8.0-44.50
linux-image-5.8.0-44-lowlatency (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-5.8.0-44-generic (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-5.8.0-44-generic-lpae (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-generic-64k-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-virtual-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-lowlatency-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-generic-lpae-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-generic-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-raspi-nolpae (Ubuntu package) - update to 5.8.0.1016.19
linux-image-5.8.0-1016-raspi (Ubuntu package) - update to 5.8.0-1016.19
linux-image-5.8.0-1016-raspi-nolpae (Ubuntu package) - update to 5.8.0-1016.19
linux-image-5.8.0-1019-kvm (Ubuntu package) - update to 5.8.0-1019.21
linux-image-5.8.0-1021-oracle (Ubuntu package) - update to 5.8.0-1021.22
linux-image-5.8.0-1023-gcp (Ubuntu package) - update to 5.8.0-1023.24
linux-image-5.8.0-1023-azure (Ubuntu package) - update to 5.8.0-1023.25
linux-image-5.8.0-1024-aws (Ubuntu package) - update to 5.8.0-1024.26
kernel - addressed in versions 5.8.17-100.fc31, 5.8.17-200.fc32, 5.8.17-300.fc33

• https://xenbits.xen.org/xsa/advisory-331.html

• Local denial of service in Xen
• Ubuntu update for linux
• Ubuntu update for linux
• Ubuntu update for linux
• Ubuntu update for linux
• Amazon Linux AMI update for kernel
• openEuler update for kernel
• Gentoo update for Xen
• Fedora 32 update for kernel
• Fedora 33 update for kernel
• Fedora 31 update for kernel