Linux Kernel prior 6.12.31/6.14.9 intel_pmu_pebs_event_update_no_drain null pointer dereference

Summaryinfo

A vulnerability classified as critical was found in Linux Kernel up to 6.12.30/6.14.8/a9d6d466bcf0621a872e1052bc40e4c6f0541b8d. The impacted element is the function intel_pmu_pebs_event_update_no_drain. The manipulation results in null pointer dereference. This vulnerability was named CVE-2025-38055. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.12.30/6.14.8/a9d6d466bcf0621a872e1052bc40e4c6f0541b8d. Affected is the function intel_pmu_pebs_event_update_no_drain. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

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.

The weakness was presented by SegFault. The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2025-38055 since 04/16/2025. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 241617 (SUSE SLES15 Security Update : kernel (SUSE-SU-2025:02254-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.31 or 6.14.9 eliminates this vulnerability. Applying the patch ca51db23166767a8445deb8331c9b8d5205d9287/0b1874a5b1173fbcb2185ab828f4c33d067e551e/99bcd91fabada0dbb1d5f0de44532d8008db93c6 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (241617) and CERT Bund (WID-SEC-2025-1350). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Avamar
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.14.0
• 6.14.1
• 6.14.2
• 6.14.3
• 6.14.4
• 6.14.5
• 6.14.6
• 6.14.7
• 6.14.8
• a9d6d466bcf0621a872e1052bc40e4c6f0541b8d

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Exploitinginfo

Threat Intelligenceinfo

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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