Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1ac7fd8159a842b3aa51f0b46a351fa3eeb8fbf3 before 625bcd0685a1612225df83468c83412fc0edb3d7; affected 1ac7fd8159a842b3aa51f0b46a351fa3eeb8fbf3 before b0380e13502adf7dd8be4c47d622c3522aae6c63 |
| Linux / Linux | affected 5.17; unaffected 0 before 5.17; unaffected 5.18.15 through 5.18.*; unaffected 5.19 through * |
CWE
No CWE identifiers supplied.