perf/core: Prevent VMA split of buffer mappings (Linux Linux)

CVE-2025-38563
HIGH 7.8

At a glance

Source
NVD
EPSS
EPSS 0.40 % · percentile 35 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Analyzed

Description

In the Linux kernel, the following vulnerability has been resolved: perf/core: Prevent VMA split of buffer mappings The perf mmap code is careful about mmap()'ing the user page with the ringbuffer and additionally the auxiliary buffer, when the event supports it. Once the first mapping is established, subsequent mapping have to use the same offset and the same size in both cases. The reference counting for the ringbuffer and the auxiliary buffer depends on this being correct. Though perf does not prevent that a related mapping is split via mmap(2), munmap(2) or mremap(2). A split of a VMA results in perf_mmap_open() calls, which take reference counts, but then the subsequent perf_mmap_close() calls are not longer fulfilling the offset and size checks. This leads to reference count leaks. As perf already has the requirement for subsequent mappings to match the initial mapping, the obvious consequence is that VMA splits, caused by resizing of a mapping or partial unmapping, have to be prevented. Implement the vm_operations_struct::may_split() callback and return unconditionally -EINVAL. That ensures that the mapping offsets and sizes cannot be changed after the fact. Remapping to a different fixed address with the same size is still possible as it takes the references for the new mapping and drops those of the old mapping.

References

Scores

VersionScoreVectorScored by
CVSS 3.1HIGH 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 45bfb2e50471abbbfd83d40d28c986078b0d24ff < e4346ffec2c44d6b0be834d59b20632b5bb5729e ; affected 45bfb2e50471abbbfd83d40d28c986078b0d24ff < d52451a9210f2e5a079ba052918c93563518a9ff ; affected 45bfb2e50471abbbfd83d40d28c986078b0d24ff < 3bd518cc7ea61076bcd725e36ff0e690754977c0 ; affected 45bfb2e50471abbbfd83d40d28c986078b0d24ff < 7b84cb58d1f0aa07656802eae24689566e5f5b1b ; affected 45bfb2e50471abbbfd83d40d28c986078b0d24ff < 6757a31a8e295ae4f01717a954afda173f25a121 ; affected 45bfb2e50471abbbfd83d40d28c986078b0d24ff < e529888b7e8092912dd8789bdfc76685ccd2ff5f
Linux · Linuxaffected 4.1 ; unaffected 0 < 4.1 ; unaffected 5.4.297 ≤ 5.4.* ; unaffected 5.10.241 ≤ 5.10.* ; unaffected 5.15.190 ≤ 5.15.* ; unaffected 6.1.148 ≤ 6.1.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD