| 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-2022-49565: perf/x86/intel/lbr: Fix unchecked MSR access error on HSW |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| perf/x86/intel/lbr: Fix unchecked MSR access error on HSW |
| |
| The fuzzer triggers the below trace. |
| |
| [ 7763.384369] unchecked MSR access error: WRMSR to 0x689 |
| (tried to write 0x1fffffff8101349e) at rIP: 0xffffffff810704a4 |
| (native_write_msr+0x4/0x20) |
| [ 7763.397420] Call Trace: |
| [ 7763.399881] <TASK> |
| [ 7763.401994] intel_pmu_lbr_restore+0x9a/0x1f0 |
| [ 7763.406363] intel_pmu_lbr_sched_task+0x91/0x1c0 |
| [ 7763.410992] __perf_event_task_sched_in+0x1cd/0x240 |
| |
| On a machine with the LBR format LBR_FORMAT_EIP_FLAGS2, when the TSX is |
| disabled, a TSX quirk is required to access LBR from registers. |
| The lbr_from_signext_quirk_needed() is introduced to determine whether |
| the TSX quirk should be applied. However, the |
| lbr_from_signext_quirk_needed() is invoked before the |
| intel_pmu_lbr_init(), which parses the LBR format information. Without |
| the correct LBR format information, the TSX quirk never be applied. |
| |
| Move the lbr_from_signext_quirk_needed() into the intel_pmu_lbr_init(). |
| Checking x86_pmu.lbr_has_tsx in the lbr_from_signext_quirk_needed() is |
| not required anymore. |
| |
| Both LBR_FORMAT_EIP_FLAGS2 and LBR_FORMAT_INFO have LBR_TSX flag, but |
| only the LBR_FORMAT_EIP_FLAGS2 requirs the quirk. Update the comments |
| accordingly. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49565 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.17 with commit 1ac7fd8159a842b3aa51f0b46a351fa3eeb8fbf3 and fixed in 5.18.15 with commit 625bcd0685a1612225df83468c83412fc0edb3d7 |
| Issue introduced in 5.17 with commit 1ac7fd8159a842b3aa51f0b46a351fa3eeb8fbf3 and fixed in 5.19 with commit b0380e13502adf7dd8be4c47d622c3522aae6c63 |
| |
| 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-2022-49565 |
| 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/events/intel/lbr.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/625bcd0685a1612225df83468c83412fc0edb3d7 |
| https://git.kernel.org/stable/c/b0380e13502adf7dd8be4c47d622c3522aae6c63 |
