CVE-2025-38322: perf/x86/intel: Fix crash in icl_update_topdown_event()
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix crash in iclupdatetopdownevent()
The perffuzzer found a hard-lockup crash on a RaptorLake machine:
Oops: general protection fault, maybe for address 0xffff89aeceab400: 0000 CPU: 23 UID: 0 PID: 0 Comm: swapper/23 Tainted: [W]=WARN Hardware name: Dell Inc. Precision 9660/0VJ762 RIP: 0010:nativereadpmc+0x7/0x40 Code: cc e8 8d a9 01 00 48 89 03 5b cd cc cc cc cc 0f 1f ... RSP: 000:fffb03100273de8 EFLAGS: 00010046 .... Call Trace: <TASK> iclupdatetopdownevent+0x165/0x190 ? ktimeget+0x38/0xd0 intelpmureadevent+0xf9/0x210 perfeventread+0xf9/0x210
CPUs 16-23 are E-core CPUs that don't support the perf metrics feature. The iclupdatetopdownevent() should not be invoked on these CPUs.
It's a regression of commit:
f9bdf1f95339 ("perf/x86/intel: Avoid disable PMU if !cpuc->enabled in sample read")
The bug introduced by that commit is that the istopdownevent() function is mistakenly used to replace the istopdowncount() call to check if the topdown functions for the perf metrics feature should be invoked.
Fix it.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Update the Linux kernel regression fix so that icl_update_topdown_event() is not invoked on E-core CPUs (CPUs 16-23 in the report) that do not support the perf metrics feature; instead, ensure the topdown functions are invoked only when supported (per the described fix for 'perf/x86/intel: Fix crash in icl_update_topdown_event()').
Linux kernel (perf/x86/intel PMU topdown event handling) Invoke icl_update_topdown_event() only on CPUs that support the perf metrics topdown functions = Do not invoke icl_update_topdown_event() on E-core CPUs that don't support the perf metrics feature
Event History
Frequently Asked Questions
What is the severity of CVE-2025-38322?
CVE-2025-38322 has been classified with a severity level that indicates a significant impact due to its potential to cause hard-lockup crashes.
How do I fix CVE-2025-38322?
To mitigate CVE-2025-38322, update to the latest version of the Linux kernel where the vulnerability has been patched.
What systems are affected by CVE-2025-38322?
CVE-2025-38322 primarily affects systems running the Linux kernel, particularly those using RaptorLake machines.
What is the exploitability of CVE-2025-38322?
CVE-2025-38322 could be exploited to induce a crash in the affected systems, leading to potential denial of service.
Is there a workaround for CVE-2025-38322?
Currently, no specific workaround is available for CVE-2025-38322, and upgrading the kernel is recommended for protection.