CVE-2025-38055: linux NULL Pointer Dereference
Vulnerability summary
CVE-2025-38055 is a medium (CVSS 5.5) NULL Pointer Dereference vulnerability in linux. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 7.7% of scored vulnerabilities.
Advisory lineage
Upstream 0 · Downstream 26 · Related 26Timeline
- 18-06-2025PublishedVulnerability first disclosed.
- 23-05-2026Last modifiedVulnerability information updated.
Description
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.
CVSS metrics
3 scores · 3 sources · 1 version- OSV · UbuntuEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated5.5MediumCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
0.19%
Chance of exploitation in the next 30 days
Percentile
8%
Versus all other CVEs
30-day change
0.00 pp
From 0.19% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
0 foundNo public exploits indexed.
Weaknesses
CWE · root causeAffected systems
Ubuntu119 products
- linux< 6.8.0-100.100
- linux-allwinner-5.19All versions (No fix recorded)
- linux-aws< 6.8.0-1046.49
- linux-aws-5.0All versions (No fix recorded)
- linux-aws-5.11All versions (No fix recorded)
Linux2 products
- linux≥ 722e42e45c2f1c6d1adec7813651dba5139f52f4, < ca51db23166767a8445deb8331c9b8d5205d9287 | ≥ 722e42e45c2f1c6d1adec7813651dba5139f52f4, < 0b1874a5b1173fbcb2185ab828f4c33d067e551e | ≥ 722e42e45c2f1c6d1adec7813651dba5139f52f4, < 99bcd91fabada0dbb1d5f0de44532d8008db93c6 | a9d6d466bcf0621a872e1052bc40e4c6f0541b8d | ≥ 6.10.5, < 6.11 | 6.11
- linux_kernel≥ 6.10.5, < 6.12.31 | ≥ 6.13, < 6.14.9 | 6.15:rc1 | 6.15:rc2 | 6.15:rc3 | 6.15:rc4 | 6.15:rc5 | 6.15:rc6
Debian1 product
- linux< 6.12.32-1
3 vendors · 122 products