Vulnerability · Published Oct 28, 2021 · Assigned by mitre
CVE-2021-43056
Medium 5.5
In plain English
A medium-severity security flaw in the bpftool package (AlmaLinux). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 31% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.4%top 69.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
An issue was discovered in the Linux kernel for powerpc before 5.14.15. It allows a malicious KVM guest to crash the host, when the host is running on Power8, due to an arch/powerpc/kvm/book3s_hv_rmhandlers.S implementation bug in the handling of the SRR1 register values.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:8 | bpftool | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-abi-stablelists | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-cross-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-core | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-debug-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-doc | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-headers | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-modules-extra | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | kernel-tools-libs-devel | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| AlmaLinux:8 | python3-perf | 4.18.0-372.9.1.el8 | ALSA-2022:1988 |
| Debian:12 | linux | 5.14.16-1 | DEBIAN-CVE-2021-43056 |
| Debian:13 | linux | 5.14.16-1 | DEBIAN-CVE-2021-43056 |
| Debian:14 | linux | 5.14.16-1 | DEBIAN-CVE-2021-43056 |
| Rocky Linux:8 | kernel | 0:4.18.0-372.9.1.el8 | RLSA-2022:1988 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2021-43056 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2021-43056 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2021-43056 |
Affected products (as reported)
References
- https://git.kernel.org/linus/cdeb5d7d890e14f3b70e8087e745c4a6a7d9f337 x_refsource_MISC
- https://lore.kernel.org/linuxppc-dev/87pmrtbbdt.fsf%40mpe.ellerman.id.au/T/#u x_refsource_MISC
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.14.15 x_refsource_MISC
- [oss-security] 20211028 Re: Linux kernel: powerpc: KVM guest can trigger host crash on Power8 mailing-list, x_refsource_MLIST
- FEDORA-2021-4320606094 vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-ed8c2e1098 vendor-advisory, x_refsource_FEDORA
- FEDORA-2021-4fed2b55c4 vendor-advisory, x_refsource_FEDORA