Description
An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device, aka CID-073d0552ead5.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 5.9.6-1 | — |
| Debian 13 | linux | 5.9.6-1 | — |
| Debian 12 | linux | 5.9.6-1 | — |
| Debian 9 | linux | 4.9.246-1 | DLA-2494-1 |
| Debian 9 | linux-4.19 | 4.19.160-2~deb9u1 | DLA-2483-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-59.65 | USN-4679-1 |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1034.35 | USN-4679-1 |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1035.36 | USN-4679-1 |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1033.35 | USN-4679-1 |
| Ubuntu 20.04 LTS | linux-hwe-5.8 | 5.8.0-44.50~20.04.1 | USN-4751-1 |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1031.32 | USN-4679-1 |
| Ubuntu 20.04 LTS | linux-oem-5.6 | 5.6.0-1050.54 | — |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1034.36 | USN-4679-1 |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1026.29 | USN-4679-1 |
| Ubuntu 20.04 LTS | linux-raspi2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-riscv | 5.4.0-40.45 | — |
| Ubuntu 20.04 LTS | linux-riscv-5.8 | 5.8.0-17.19~20.04.1 | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-129.132 | USN-4680-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1091.96 | USN-4680-1 |
| Ubuntu 18.04 LTS | linux-aws-5.4 | 5.4.0-1034.35~18.04.1 | USN-4679-1 |
| Ubuntu 18.04 LTS | linux-azure-4.15 | 4.15.0-1103.114 | USN-4680-1 |
| Ubuntu 18.04 LTS | linux-azure-5.4 | 5.4.0-1035.36~18.04.1 | USN-4679-1 |
| Ubuntu 18.04 LTS | linux-dell300x | 4.15.0-1010.14 | — |
| Ubuntu 18.04 LTS | linux-gcp +12 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-4.15 | 4.15.0-1091.104 | USN-4680-1 |
| Ubuntu 18.04 LTS | linux-gcp-5.4 +1 | 5.4.0-1033.35~18.04.1 | USN-4679-1 |
| Ubuntu 18.04 LTS | linux-gkeop-5.4 | 5.4.0-1008.9~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-59.65~18.04.1 | USN-4679-1 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1082.84 | USN-4680-1 |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1062.68 | USN-4680-1 |
| Ubuntu 18.04 LTS | linux-oracle-5.4 | 5.4.0-1034.36~18.04.1 | USN-4679-1 |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1026.29~18.04.1 | USN-4679-1 |
| Ubuntu 18.04 LTS | linux-raspi2 +1 | 4.15.0-1077.82 | USN-4680-1 |
| Ubuntu 18.04 LTS | linux-snapdragon | 4.15.0-1094.103 | USN-4680-1 |
| Ubuntu 16.04 LTS | linux | 4.4.0-198.230 | USN-4681-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1119.133 | USN-4681-1 |
| Ubuntu 16.04 LTS | linux-aws-hwe | 4.15.0-1091.96~16.04.1 | USN-4680-1 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1103.114~16.04.1 | USN-4680-1 |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1091.104~16.04.1 | USN-4680-1 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-129.132~16.04.1 | USN-4680-1 |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1085.94 | USN-4681-1 |
| Ubuntu 16.04 LTS | linux-oracle | 4.15.0-1062.68~16.04.1 | USN-4680-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1143.153 | USN-4681-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1147.157 | USN-4681-1 |
Show 8 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | linux-aws-fips +2 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1069.73+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1073.76+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1067.71~20.04.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-aws-fips | 4.15.0-2034.35 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-azure-fips | 4.15.0-2016.18 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips | 4.15.0-1049.56 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1052.58 | — |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1114.123~20.04.1 | — |
| Ubuntu Pro 14.04 LTS | linux | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-aws | 4.4.0-1083.87 | USN-4681-1 |
| Ubuntu Pro 14.04 LTS | linux-azure | 4.15.0-1103.114~14.04.1 | USN-4680-1 |
| Ubuntu Pro 14.04 LTS | linux-lts-xenial | 4.4.0-198.230~14.04.1 | USN-4681-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | kernel-azure +2 | 5.3.18-18.24.1 | SUSE-SU-2020:3491-1 |
| SLES 15 SP1 | kernel-docs +5 | 4.12.14-197.67.1 | SUSE-SU-2020:3272-1 |
| SLES 15 | kernel-docs +6 | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SLES 12 SP5 | kernel-azure +2 | 4.12.14-16.34.1 | SUSE-SU-2020:3281-1 |
| SLES 12 SP4 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 | kernel-docs +5 | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SLES for SAP 12 SP5 | kernel-azure +2 | 4.12.14-16.34.1 | SUSE-SU-2020:3281-1 |
| SLES for SAP 12 SP4 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
| SLE Live Patching 15 SP1 | kernel-default | 4.12.14-197.67.1 | SUSE-SU-2020:3272-1 |
| SLE Live Patching 15 SP1 | kernel-livepatch-SLE15-SP1_Update_18 | 1-3.3.1 | SUSE-SU-2020:3272-1 |
| SLE Live Patching 15 | kernel-default | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SLE Live Patching 15 | kernel-livepatch-SLE15_Update_21 | 1-1.5.1 | SUSE-SU-2020:3532-1 |
| SLE Live Patching 12 SP4 | kernel-default | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
| SLE Live Patching 12 SP4 | kgraft-patch-SLE12-SP4_Update_17 | 1-6.5.1 | SUSE-SU-2020:3544-1 |
| SLE HPC 15 | kernel-docs +5 | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SUSE OpenStack Cloud Crowbar 9 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
| SUSE OpenStack Cloud 9 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | kernel-livepatch-4.14.209-160.335 | 1.0-0.amzn2 | ALAS2-2020-1566 |
| Amazon Linux 2 | perf +8 | 4.14.209-160.335.amzn2 | ALAS2-2020-1566 |
Advisories 12
- USN-4681-1 linux, linux-aws, linux-kvm, linux-lts-xenial, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4679-1 linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4680-1 linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gcp-4.15, linux-gke-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4751-1 linux, linux-aws, linux-azure, linux-gcp, linux-hwe-5.8, linux-kvm, linux-oracle, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- DLA-2494-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2483-1 linux-4.19 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:3544-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3491-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3532-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3281-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3272-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · May 2, 2025
- ALAS2-2020-1566 Important: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Dec 8, 2020
References
- https://xenbits.xen.org/xsa/advisory-331.html
- https://github.com/torvalds/linux/commit/073d0552ead5bfc7a3a9c01de590e924f11b5dd2
- https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=073d0552ead5bfc7a3a9c01de590e924f11b5dd2
- FEDORA-2020-474d747b60 vendor-advisory
- FEDORA-2020-09e4d062fe vendor-advisory
- FEDORA-2020-920a258c79 vendor-advisory
- GLSA-202011-06 vendor-advisory
- [debian-lts-announce] 20201210 [SECURITY] [DLA 2483-1] linux-4.19 security update mailing-list
- [debian-lts-announce] 20201218 [SECURITY] [DLA 2494-1] linux security update mailing-list
- [oss-security] 20210119 Xen Security Advisory 331 v3 (CVE-2020-27675) - Race condition in Linux event handler may crash dom0 mailing-list