Description
long running loops in grant table handling In order to properly monitor resource use, Xen maintains information on the grant mappings a domain may create to map grants offered by other domains. In the process of carrying out certain actions, Xen would iterate over all such entries, including ones which aren't in use anymore and some which may have been created but never used. If the number of entries for a given domain is large enough, this iterating of the entire table may tie up a CPU for too long, starving other domains or causing issues in the hypervisor itself. Note that a domain may map its own grants, i.e. there is no need for multiple domains to be involved here. A pair of "cooperating" guests may, however, cause the effects to be more severe.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Xen | xen | 4.14.x, 4.15.x – < unspecified, 4.13.x, 4.11.x, 4.12.x | unspecified |
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 | xen | 4.14.3-1 | — |
| Debian 13 | xen | 4.14.3-1 | — |
| Debian 12 | xen | 4.14.3-1 | — |
| Debian 11 | xen | 4.14.3-1~deb11u1 | DSA-4977-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | xen | No fix yet | — |
| Ubuntu 26.04 LTS | xen | No fix yet | — |
| Ubuntu 25.10 | xen | No fix yet | — |
| Ubuntu 24.04 LTS | xen | No fix yet | — |
| Ubuntu 22.04 LTS | xen | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | xen | No fix yet | — |
| Ubuntu 18.04 LTS | xen | No fix yet | — |
| Ubuntu 16.04 LTS | xen | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP3 | xen | 4.14.2_04-3.9.1 | SUSE-SU-2021:2923-1 |
| SLES 15 SP2 | xen | 4.13.3_02-3.34.1 | SUSE-SU-2021:2922-1 |
| SLES 15 SP1 | xen | 4.12.4_12-3.52.1 | SUSE-SU-2021:2925-1 |
| SLES 12 SP5 | xen | 4.12.4_12-3.49.1 | SUSE-SU-2021:2924-1 |
| SLES 12 SP4 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
Show 20 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SLES 12 SP2 | xen | 4.7.6_16-43.79.5 | SUSE-SU-2021:3322-1 |
| SLES 11 SP4 | xen | 4.4.4_50-61.67.1 | SUSE-SU-2021:14848-1 |
| SLES for SAP 15 SP1 | xen | 4.12.4_12-3.52.1 | SUSE-SU-2021:2925-1 |
| SLES for SAP 15 | xen | 4.10.4_26-3.61.1 | SUSE-SU-2021:2943-1 |
| SLES for SAP 12 SP5 | xen | 4.12.4_12-3.49.1 | SUSE-SU-2021:2924-1 |
| SLES for SAP 12 SP4 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
| SLES for SAP 12 SP3 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SLE Micro 5.0 | xen | 4.13.3_02-3.34.1 | SUSE-SU-2021:2922-1 |
| SLE HPC 15 SP1 | xen | 4.12.4_12-3.52.1 | SUSE-SU-2021:2925-1 |
| SLE HPC 15 | xen | 4.10.4_26-3.61.1 | SUSE-SU-2021:2943-1 |
| SUSE OpenStack Cloud Crowbar 9 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
| SUSE OpenStack Cloud Crowbar 8 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SUSE OpenStack Cloud 9 | xen | 4.11.4_20-2.60.1 | SUSE-SU-2021:2955-1 |
| SUSE OpenStack Cloud 8 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SUSE Manager Server 4.0 | xen | 4.12.4_12-3.52.1 | SUSE-SU-2021:2925-1 |
| SUSE Manager Retail Branch Server 4.0 | xen | 4.12.4_12-3.52.1 | SUSE-SU-2021:2925-1 |
| SUSE Manager Proxy 4.0 | xen | 4.12.4_12-3.52.1 | SUSE-SU-2021:2925-1 |
| SUSE HPE Helion OpenStack 8 | xen | 4.9.4_20-3.91.1 | SUSE-SU-2021:2957-1 |
| SUSE Enterprise Storage 6 | xen | 4.12.4_12-3.52.1 | SUSE-SU-2021:2925-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.3 | xen | 4.14.2_04-3.9.1 | openSUSE-SU-2021:2923-1 |
| openSUSE Leap 15.2 | xen | 4.13.3_02-lp152.2.27.1 | openSUSE-SU-2021:1236-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | xen | 4.15.0-r2 | — |
| Alpine v3.23 | xen | 4.15.0-r2 | — |
| Alpine v3.22 | xen | 4.15.0-r2 | — |
| Alpine v3.21 | xen | 4.15.0-r2 | — |
| Alpine v3.20 | xen | 4.15.0-r2 | — |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | xen | 4.15.0-r2 | — |
| Alpine v3.18 | xen | 4.15.0-r2 | — |
| Alpine v3.17 | xen | 4.15.0-r2 | — |
| Alpine v3.16 | xen | 4.15.0-r2 | — |
| Alpine v3.15 | xen | 4.15.0-r2 | — |
| Alpine v3.14 | xen | 4.15.0-r2 | — |
| Alpine v3.13 | xen | 4.14.2-r0 | — |
| Alpine v3.12 | xen | 4.13.3-r2 | — |
| Alpine v3.11 | xen | 4.13.3-r2 | — |
Advisories 12
- DSA-4977-1 xen - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2021:2955-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2924-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:3322-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2922-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2943-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2957-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:2923-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:1236-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:2925-1 Security update for xen SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14848-1 Security update for xen SUSE / openSUSE Security Updates · May 2, 2025
- SUSE-SU-2021:2923-1 Security update for xen SUSE / openSUSE Security Updates · May 2, 2025
References
- https://xenbits.xenproject.org/xsa/advisory-380.txt
- [oss-security] 20210901 Xen Security Advisory 380 v3 (CVE-2021-28698) - long running loops in grant table handling mailing-list
- FEDORA-2021-4f129cc0c1 vendor-advisory
- FEDORA-2021-d68ed12e46 vendor-advisory
- DSA-4977 vendor-advisory
- FEDORA-2021-081f9bf5d2 vendor-advisory
- GLSA-202208-23 vendor-advisory