| 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-2023-52740: powerpc/64s/interrupt: Fix interrupt exit race with security mitigation switch |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| powerpc/64s/interrupt: Fix interrupt exit race with security mitigation switch |
| |
| The RFI and STF security mitigation options can flip the |
| interrupt_exit_not_reentrant static branch condition concurrently with |
| the interrupt exit code which tests that branch. |
| |
| Interrupt exit tests this condition to set MSR[EE|RI] for exit, then |
| again in the case a soft-masked interrupt is found pending, to recover |
| the MSR so the interrupt can be replayed before attempting to exit |
| again. If the condition changes between these two tests, the MSR and irq |
| soft-mask state will become corrupted, leading to warnings and possible |
| crashes. For example, if the branch is initially true then false, |
| MSR[EE] will be 0 but PACA_IRQ_HARD_DIS clear and EE may not get |
| enabled, leading to warnings in irq_64.c. |
| |
| The Linux kernel CVE team has assigned CVE-2023-52740 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.14 with commit 13799748b957bc5659f97c036224b0f4b42172e2 and fixed in 5.15.94 with commit 86f7e423933608d536015a0f2eb9e0338c1227e0 |
| Issue introduced in 5.14 with commit 13799748b957bc5659f97c036224b0f4b42172e2 and fixed in 6.1.12 with commit 6f097c24815e67909a1fcc2c605586d02babd673 |
| Issue introduced in 5.14 with commit 13799748b957bc5659f97c036224b0f4b42172e2 and fixed in 6.2 with commit 2ea31e2e62bbc4d11c411eeb36f1b02841dbcab1 |
| |
| 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-2023-52740 |
| 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/powerpc/kernel/interrupt.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/86f7e423933608d536015a0f2eb9e0338c1227e0 |
| https://git.kernel.org/stable/c/6f097c24815e67909a1fcc2c605586d02babd673 |
| https://git.kernel.org/stable/c/2ea31e2e62bbc4d11c411eeb36f1b02841dbcab1 |
