| 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-2023-52633: um: time-travel: fix time corruption |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| um: time-travel: fix time corruption |
| |
| In 'basic' time-travel mode (without =inf-cpu or =ext), we |
| still get timer interrupts. These can happen at arbitrary |
| points in time, i.e. while in timer_read(), which pushes |
| time forward just a little bit. Then, if we happen to get |
| the interrupt after calculating the new time to push to, |
| but before actually finishing that, the interrupt will set |
| the time to a value that's incompatible with the forward, |
| and we'll crash because time goes backwards when we do the |
| forwarding. |
| |
| Fix this by reading the time_travel_time, calculating the |
| adjustment, and doing the adjustment all with interrupts |
| disabled. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52633 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.15.149 with commit 0c7478a2da3f5fe106b4658338873d50c86ac7ab |
| Fixed in 6.1.77 with commit 4f7dad73df4cdb2b7042103d3922745d040ad025 |
| Fixed in 6.6.16 with commit de3e9d8e8d1ae0a4d301109d1ec140796901306c |
| Fixed in 6.7.4 with commit b427f55e9d4185f6f17cc1e3296eb8d0c4425283 |
| Fixed in 6.8 with commit abe4eaa8618bb36c2b33e9cdde0499296a23448c |
| |
| 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-2023-52633 |
| 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/um/kernel/time.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/0c7478a2da3f5fe106b4658338873d50c86ac7ab |
| https://git.kernel.org/stable/c/4f7dad73df4cdb2b7042103d3922745d040ad025 |
| https://git.kernel.org/stable/c/de3e9d8e8d1ae0a4d301109d1ec140796901306c |
| https://git.kernel.org/stable/c/b427f55e9d4185f6f17cc1e3296eb8d0c4425283 |
| https://git.kernel.org/stable/c/abe4eaa8618bb36c2b33e9cdde0499296a23448c |
