| 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-2024-50193: x86/entry_32: Clear CPU buffers after register restore in NMI return |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| x86/entry_32: Clear CPU buffers after register restore in NMI return |
| |
| CPU buffers are currently cleared after call to exc_nmi, but before |
| register state is restored. This may be okay for MDS mitigation but not for |
| RDFS. Because RDFS mitigation requires CPU buffers to be cleared when |
| registers don't have any sensitive data. |
| |
| Move CLEAR_CPU_BUFFERS after RESTORE_ALL_NMI. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50193 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.10.215 with commit 50f021f0b985629accf10481a6e89af8b9700583 and fixed in 5.10.228 with commit 6f44a5fc15b5cece0785bc07453db77d99b0a6de |
| Issue introduced in 5.15.154 with commit d54de9f2a127090f2017184e8257795b487d5312 and fixed in 5.15.169 with commit b6400eb0b347821efc57760221f8fb6d63b9548a |
| Issue introduced in 6.1.81 with commit 2e3087505ddb8ba2d3d4c81306cca11e868fcdb9 and fixed in 6.1.114 with commit 43778de19d2ef129636815274644b9c16e78c66b |
| Issue introduced in 6.6.21 with commit ca13d8cd8dac25558da4ee8df4dc70e8e7f9d762 and fixed in 6.6.58 with commit 227358e89703c344008119be7e8ffa3fdb5b92de |
| Issue introduced in 6.8 with commit a0e2dab44d22b913b4c228c8b52b2a104434b0b3 and fixed in 6.11.5 with commit 64adf22c4bc73ede920baca5defefb70f190cdbc |
| Issue introduced in 6.8 with commit a0e2dab44d22b913b4c228c8b52b2a104434b0b3 and fixed in 6.12 with commit 48a2440d0f20c826b884e04377ccc1e4696c84e9 |
| Issue introduced in 6.7.9 with commit 51eca9f1fd047b500137d021f882d93f03280118 |
| |
| 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-2024-50193 |
| 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/entry/entry_32.S |
| |
| |
| 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/6f44a5fc15b5cece0785bc07453db77d99b0a6de |
| https://git.kernel.org/stable/c/b6400eb0b347821efc57760221f8fb6d63b9548a |
| https://git.kernel.org/stable/c/43778de19d2ef129636815274644b9c16e78c66b |
| https://git.kernel.org/stable/c/227358e89703c344008119be7e8ffa3fdb5b92de |
| https://git.kernel.org/stable/c/64adf22c4bc73ede920baca5defefb70f190cdbc |
| https://git.kernel.org/stable/c/48a2440d0f20c826b884e04377ccc1e4696c84e9 |
