| From bippy-1.2.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2021-47112: x86/kvm: Teardown PV features on boot CPU as well |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| x86/kvm: Teardown PV features on boot CPU as well |
| |
| Various PV features (Async PF, PV EOI, steal time) work through memory |
| shared with hypervisor and when we restore from hibernation we must |
| properly teardown all these features to make sure hypervisor doesn't |
| write to stale locations after we jump to the previously hibernated kernel |
| (which can try to place anything there). For secondary CPUs the job is |
| already done by kvm_cpu_down_prepare(), register syscore ops to do |
| the same for boot CPU. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47112 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.38 with commit fd10cde9294f73eeccbc16f3fec1ae6cde7b800c and fixed in 5.4.125 with commit 7620a669111b52f224d006dea9e1e688e2d62c54 |
| Issue introduced in 2.6.38 with commit fd10cde9294f73eeccbc16f3fec1ae6cde7b800c and fixed in 5.10.43 with commit 38b858da1c58ad46519a257764e059e663b59ff2 |
| Issue introduced in 2.6.38 with commit fd10cde9294f73eeccbc16f3fec1ae6cde7b800c and fixed in 5.12.10 with commit d1629b5b925de9b27979e929dae7fcb766daf6b6 |
| Issue introduced in 2.6.38 with commit fd10cde9294f73eeccbc16f3fec1ae6cde7b800c and fixed in 5.13 with commit 8b79feffeca28c5459458fe78676b081e87c93a4 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-47112 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| arch/x86/kernel/kvm.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/7620a669111b52f224d006dea9e1e688e2d62c54 |
| https://git.kernel.org/stable/c/38b858da1c58ad46519a257764e059e663b59ff2 |
| https://git.kernel.org/stable/c/d1629b5b925de9b27979e929dae7fcb766daf6b6 |
| https://git.kernel.org/stable/c/8b79feffeca28c5459458fe78676b081e87c93a4 |
