| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2023-52942: cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| cgroup/cpuset: Fix wrong check in update_parent_subparts_cpumask() |
| |
| It was found that the check to see if a partition could use up all |
| the cpus from the parent cpuset in update_parent_subparts_cpumask() |
| was incorrect. As a result, it is possible to leave parent with no |
| effective cpu left even if there are tasks in the parent cpuset. This |
| can lead to system panic as reported in [1]. |
| |
| Fix this probem by updating the check to fail the enabling the partition |
| if parent's effective_cpus is a subset of the child's cpus_allowed. |
| |
| Also record the error code when an error happens in update_prstate() |
| and add a test case where parent partition and child have the same cpu |
| list and parent has task. Enabling partition in the child will fail in |
| this case. |
| |
| [1] https://www.spinics.net/lists/cgroups/msg36254.html |
| |
| The Linux kernel CVE team has assigned CVE-2023-52942 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.1 with commit f0af1bfc27b52a4d42510051154c61bd176a8f06 and fixed in 6.1.11 with commit a2ab7f2cf5ef8f0c6212a246e681d1fe358cec1f |
| Issue introduced in 6.1 with commit f0af1bfc27b52a4d42510051154c61bd176a8f06 and fixed in 6.2 with commit e5ae8803847b80fe9d744a3174abe2b7bfed222a |
| |
| 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-2023-52942 |
| 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: |
| kernel/cgroup/cpuset.c |
| tools/testing/selftests/cgroup/test_cpuset_prs.sh |
| |
| |
| 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/a2ab7f2cf5ef8f0c6212a246e681d1fe358cec1f |
| https://git.kernel.org/stable/c/e5ae8803847b80fe9d744a3174abe2b7bfed222a |
