CVE-2025-38055
What it is
In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix segfault with PEBS-via-PT with sample_freq Currently, using PEBS-via-PT with a sample frequency instead of a sample period, causes a segfault. For example: BUG: kernel NULL pointer dereference, address: 0000000000000195 <NMI> ? __die_body.cold+0x19/0x27 ? page_fault_oops+0xca/0x290 ? exc_page_fault+0x7e/0x1b0 ? asm_exc_page_fault+0x26/0x30 ? intel_pmu_pebs_event_update_no_drain+0x40/0x60 ? intel_pmu_pebs_event_update_no_drain+0x32/0x60 intel_pmu_drain_pebs_icl+0x333/0x350 handle_pmi_common+0x272/0x3c0 intel_pmu_handle_irq+0x10a/0x2e0 perf_event_nmi_handler+0x2a/0x50 That happens because intel_pmu_pebs_event_update_no_drain() assumes all the pebs_enabled bits represent counter indexes, which is not always the case. In this particular case, bits 60 and 61 are set for PEBS-via-PT purposes. The behaviour of PEBS-via-PT with sample frequency is questionable because although a PMI is generated (PEBS_PMI_AFTER_EACH_RECORD), the period is not adjusted anyway. Putting that aside, fix intel_pmu_pebs_event_update_no_drain() by passing the mask of counter bits instead of 'size'. Note, prior to the Fixes commit, 'size' would be limited to the maximum counter index, so the issue was not hit.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-476 · NULL pointer dereference
- Record status
- Analyzed
Affected
- Linux Kernel < 6.12.31
- Linux Kernel < 6.14.9
- Linux Kernel 6.15
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-38055.md and follow it. Check whether this project is affected by CVE-2025-38055. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/0b1874a5b1173fbcb2185ab828f4c33d067e551e
- https://git.kernel.org/stable/c/99bcd91fabada0dbb1d5f0de44532d8008db93c6
- https://git.kernel.org/stable/c/ca51db23166767a8445deb8331c9b8d5205d9287