Bug 2507047 (CVE-2026-64318)
| Summary: | CVE-2026-64318 kernel: partitions: aix: bound the pp_count scan to the ppe array | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | unspecified | CC: | rhel-process-autobot, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's AIX partition handling. A local attacker can provide a specially crafted AIX/IBM partition table on a block device. When the kernel scans this device, the `aix_partition()` function reads an unvalidated `pp_count` value, causing it to read beyond the allocated buffer. This out-of-bounds read can lead to information disclosure, potentially revealing sensitive kernel memory, and may also result in a denial of service.
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: partitions: aix: bound the pp_count scan to the ppe array aix_partition() reads the physical volume descriptor into a fixed-size struct pvd and then scans its physical-partition-extent array: int numpps = be16_to_cpu(pvd->pp_count); ... for (i = 0; i < numpps; i += 1) { struct ppe *p = pvd->ppe + i; ... lp_ix = be16_to_cpu(p->lp_ix); pvd points at a single kmalloc()'d struct pvd whose ppe[] member holds a fixed ARRAY_SIZE(pvd->ppe) (1016) entries, but the loop runs up to the on-disk pp_count. pp_count is an unvalidated __be16 read straight from the descriptor, so a crafted AIX image with pp_count larger than 1016 drives the loop to read pvd->ppe[i] past the end of the allocation (up to 65535 entries, ~2 MB out of bounds). The partition scan runs without mounting anything, when a block device with a crafted AIX/IBM partition table appears (an attacker-supplied image attached with losetup -P, or a device auto-scanned by udev), via msdos_partition() -> aix_partition(). Clamp the scan to the number of entries the ppe[] array can hold.