| 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-2022-49640: sysctl: Fix data races in proc_douintvec_minmax(). |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| sysctl: Fix data races in proc_douintvec_minmax(). |
| |
| A sysctl variable is accessed concurrently, and there is always a chance |
| of data-race. So, all readers and writers need some basic protection to |
| avoid load/store-tearing. |
| |
| This patch changes proc_douintvec_minmax() to use READ_ONCE() and |
| WRITE_ONCE() internally to fix data-races on the sysctl side. For now, |
| proc_douintvec_minmax() itself is tolerant to a data-race, but we still |
| need to add annotations on the other subsystem's side. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49640 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.13 with commit 61d9b56a89208d8cccd0b4cfec7e6959717e16e3 and fixed in 5.10.132 with commit e3a2144b3b6bf9ecafd91087c8b8b48171ec19df |
| Issue introduced in 4.13 with commit 61d9b56a89208d8cccd0b4cfec7e6959717e16e3 and fixed in 5.15.56 with commit 40e0477a7371d101c55b69d9c32a7a1ed82ab5ea |
| Issue introduced in 4.13 with commit 61d9b56a89208d8cccd0b4cfec7e6959717e16e3 and fixed in 5.18.13 with commit b60eddf98b9716651069dfda296c91311a7a6293 |
| Issue introduced in 4.13 with commit 61d9b56a89208d8cccd0b4cfec7e6959717e16e3 and fixed in 5.19 with commit 2d3b559df3ed39258737789aae2ae7973d205bc1 |
| |
| 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-2022-49640 |
| 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/sysctl.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/e3a2144b3b6bf9ecafd91087c8b8b48171ec19df |
| https://git.kernel.org/stable/c/40e0477a7371d101c55b69d9c32a7a1ed82ab5ea |
| https://git.kernel.org/stable/c/b60eddf98b9716651069dfda296c91311a7a6293 |
| https://git.kernel.org/stable/c/2d3b559df3ed39258737789aae2ae7973d205bc1 |
