{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "fec56f5890d93fc2ed74166c397dc186b1c25951"
            },
            {
              "fixed": "d36ac53fc83baf843c51b7afd6d2471f36b713d8"
            },
            {
              "fixed": "c48796aa6c392cde93946e5d5a9a1f1b1cf72feb"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.5.0"
            },
            {
              "fixed": "7.2.6"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90359.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Reject \u003e8 byte return values on return-reading trampoline paths\n\nbtf_distill_func_proto() builds the function model used for the\nfentry/fexit/fmod_ret/fsession trampolines and struct_ops. It has\naccepted a 16-byte __int128 return value since the trampoline was\nintroduced: __get_type_size() returns the integer's type size, and the\nreturn-type check only rejected ret \u003c 0.\n\nBut the BPF trampoline preserves only 8 bytes of the return value (RAX on\nx86, i.e. R0). For an attach type that reads the target's return value the\nsecond half (RDX / R3) is neither saved nor restored, so a program\nattached to a function returning a 16-byte value corrupts the value seen\nby the real caller and itself observes only half of it. struct_ops\ntrampolines have the same limitation.\n\nThis affects the attach types that read the target's return value: fexit,\nfmod_ret and fsession (plus the _multi variants of fexit and fsession),\nand struct_ops. fentry/fentry_multi run before the target returns and are\nunaffected.\n\nReject a \u003e8 byte return value for these attach types in\nbpf_check_attach_target() and bpf_check_attach_btf_id_multi(), and for\nstruct_ops in bpf_struct_ops_desc_init().",
  "id": "CVE-2026-90359",
  "modified": "2026-09-19T03:30:41.752603001Z",
  "published": "2026-09-17T16:09:04.187Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c48796aa6c392cde93946e5d5a9a1f1b1cf72feb"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d36ac53fc83baf843c51b7afd6d2471f36b713d8"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/90xxx/CVE-2026-90359.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-90359"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "bpf: Reject \u003e8 byte return values on return-reading trampoline paths"
}