CVE-2022-49565 perf/x86/intel/lbr: Fix unchecked MSR access error on HSW
A logic error in the Linux kernel's Intel LBR handling causes unchecked MSR access errors, potentially leading to system crashes or denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-49565?
CVE-2022-49565 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official 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.
Which versions are affected by CVE-2022-49565?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49565?
Apply the vendor's patch.
Is CVE-2022-49565 being exploited?
There is no known exploitation of CVE-2022-49565 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49565, GHSA-555r-f9m4-vp82, UBUNTU-CVE-2022-49565.