powerpc64/ftrace: fix clobbered r15 during livepatching

{
  "id": "6bddd9a3618329ebcfd5c4e948c83ed5ed2515b2c7b980778249c11165916154",
  "url": "https://osv.dev/vulnerability/CVE-2025-38233",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "powerpc64/ftrace: fix clobbered r15 during livepatching",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: powerpc64/ftrace: fix clobbered r15 during livepatching While r15 is clobbered always with PPC_FTRACE_OUT_OF_LINE, it is not restored in livepatch sequence leading to not so obvious fails like below: BUG: Unable to handle kernel data access on write at 0xc0000000000f9078 Faulting instruction address: 0xc0000000018ff958 Oops: Kernel access of bad area, sig: 11 [#1] ... NIP: c0000000018ff958 LR: c0000000018ff930 CTR: c0000000009c0790 REGS: c00000005f2e7790 TRAP: 0300 Tainted: G K (6.14.0+) MSR: 8000000000009033 CR: 2822880b XER: 20040000 CFAR: c0000000008addc0 DAR: c0000000000f9078 DSISR: 0a000000 IRQMASK: 1 GPR00: c0000000018f2584 c00000005f2e7a30 c00000000280a900 c000000017ffa488 GPR04: 0000000000000008 0000000000000000 c0000000018f24fc 000000000000000d GPR08: fffffffffffe0000 000000000000000d 0000000000000000 0000000000008000 GPR12: c0000000009c0790 c000000017ffa480 c00000005f2e7c78 c0000000000f9070 GPR16: c00000005f2e7c90 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000000 c00000005f3efa80 c00000005f2e7c60 c00000005f2e7c88 GPR24: c00000005f2e7c60 0000000000000001 c0000000000f9078 0000000000000000 GPR28: 00007fff97960000 c000000017ffa480 0000000000000000 c0000000000f9078 ... Call Trace: check_heap_object+0x34/0x390 (unreliable) __mutex_unlock_slowpath.isra.0+0xe4/0x230 seq_read_iter+0x430/0xa90 proc_reg_read_iter+0xa4/0x200 vfs_read+0x41c/0x510 ksys_read+0xa4/0x190 system_call_exceptio",
    "evidence": "osv:CVE-2025-38233",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.15.4",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2025-38233",
      "aliases": [
        "CVE-2025-38233"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "eec37961a56aa4f3fe1c33ffd48eec7d1bb0c009"
                },
                {
                  "fixed": "a9212bf5ca640232254b31330e86272fe4073bc9"
                },
                {
                  "fixed": "cb5b691f8273432297611863ac142e17119279e0"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38233.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.13.0"
                },
                {
                  "fixed": "6.15.4"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-38233.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.089571421Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/a9212bf5ca640232254b31330e86272fe4073bc9",
        "https://git.kernel.org/stable/c/cb5b691f8273432297611863ac142e17119279e0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38233.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-38233",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/38xxx/CVE-2025-38233.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-38233",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493649,
  "published_at": "2025-07-04T13:37:46.293+00:00"
}