bpf: Fix abuse of kprobe_write_ctx via freplace

{
  "id": "b4fbdd939b4b3cd61df69f03620f52a5222e34b841da46c80f803bb3c79d58f7",
  "url": "https://osv.dev/vulnerability/CVE-2026-53095",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "bpf: Fix abuse of kprobe_write_ctx via freplace",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: bpf: Fix abuse of kprobe_write_ctx via freplace uprobe programs are allowed to modify struct pt_regs. Since the actual program type of uprobe is KPROBE, it can be abused to modify struct pt_regs via kprobe+freplace when the kprobe attaches to kernel functions. For example, SEC(\"?kprobe\") int kprobe(struct pt_regs *regs) { return 0; } SEC(\"?freplace\") int freplace_kprobe(struct pt_regs *regs) { regs->di = 0; return 0; } freplace_kprobe prog will attach to kprobe prog. kprobe prog will attach to a kernel function. Without this patch, when the kernel function runs, its first arg will always be set as 0 via the freplace_kprobe prog. To fix the abuse of kprobe_write_ctx=true via kprobe+freplace, disallow attaching freplace programs on kprobe programs with different kprobe_write_ctx values.",
    "evidence": "osv:CVE-2026-53095",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.33",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.10",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-53095",
      "aliases": [
        "CVE-2026-53095"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "7384893d970ea114952aef54ad7e3d7d2ca82d4f"
                },
                {
                  "fixed": "b312cf41b9e43f442613053f6cad39898e1baf96"
                },
                {
                  "fixed": "9836cadbd96c7e0dbb0018fa60e7872dd31ac4f8"
                },
                {
                  "fixed": "611fe4b79af72d00d80f2223354284447daafae9"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53095.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.18.0"
                },
                {
                  "fixed": "6.18.33"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.10"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53095.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:39.240513937Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/611fe4b79af72d00d80f2223354284447daafae9",
        "https://git.kernel.org/stable/c/9836cadbd96c7e0dbb0018fa60e7872dd31ac4f8",
        "https://git.kernel.org/stable/c/b312cf41b9e43f442613053f6cad39898e1baf96",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53095.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-53095",
        "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/2026/53xxx/CVE-2026-53095.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-53095",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 506415,
  "published_at": "2026-06-24T16:30:33.684+00:00"
}