Answer in brief
CVE-2025-38563 records a Unknown severity vulnerability in perf/core: Prevent VMA split of buffer mappings. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <e4346ffec2c44d6b0be834d59b20632b5bb5729e || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <d52451a9210f2e5a079ba052918c93563518a9ff || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <3bd518cc7ea61076bcd725e36ff0e690754977c0 || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <7b84cb58d1f0aa07656802eae24689566e5f5b1b || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <6757a31a8e295ae4f01717a954afda173f25a121 || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <e529888b7e8092912dd8789bdfc76685ccd2ff5f || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <ff668930871e0198c7f4e325058b8b7c286787bd || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <65311aad4c808bedad0c05d9bb8b06c47dae73eb || >=45bfb2e50471abbbfd83d40d28c986078b0d24ff <b024d7b56c77191cde544f838debb7f8451cd0d6 | e4346ffec2c44d6b0be834d59b20632b5bb5729e, d52451a9210f2e5a079ba052918c93563518a9ff, 3bd518cc7ea61076bcd725e36ff0e690754977c0, 7b84cb58d1f0aa07656802eae24689566e5f5b1b, 6757a31a8e295ae4f01717a954afda173f25a121, e529888b7e8092912dd8789bdfc76685ccd2ff5f, ff668930871e0198c7f4e325058b8b7c286787bd, 65311aad4c808bedad0c05d9bb8b06c47dae73eb, b024d7b56c77191cde544f838debb7f8451cd0d6 |
| Linux/Linuxgeneric | 4.1 | Not reported |
Published upstream
Aug 19, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.