{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-39965",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2025-39965"
  ],
  "published": "2025-10-13T13:48:42Z",
  "summary": "xfrm: xfrm_alloc_spi shouldn't use 0 as SPI",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: xfrm_alloc_spi shouldn't use 0 as SPI\n\nx->id.spi == 0 means \"no SPI assigned\", but since commit\n94f39804d891 (\"xfrm: Duplicate SPI Handling\"), we now create states\nand add them to the byspi list with this value.\n\n__xfrm_state_delete doesn't remove those states from the byspi list,\nsince they shouldn't be there, and this shows up as a UAF the next\ntime we go through the byspi list.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.12.47-1+rpt1~bookworm"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-2712",
            "binary_version": "1:6.12.47-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v6",
            "binary_version": "1:6.12.47-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v7",
            "binary_version": "1:6.12.47-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v7l",
            "binary_version": "1:6.12.47-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v8",
            "binary_version": "1:6.12.47-1+rpt1~bookworm"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.47-1+rpt1~bookworm"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.12.47-1+rpt1~bookworm": {
            "linux_commit": "359f37f0faefb712add32a39f98751aea67d5c1f",
            "upstream_version": "6.12.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.50"
          }
        }
      }
    },
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:13",
        "name": "linux"
      },
      "versions": [
        "1:6.12.47-1+rpt1"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-2712",
            "binary_version": "1:6.12.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v6",
            "binary_version": "1:6.12.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v7",
            "binary_version": "1:6.12.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v8",
            "binary_version": "1:6.12.47-1+rpt1"
          },
          {
            "binary_name": "linux-image-6.12.47+rpt-rpi-v8-rt",
            "binary_version": "1:6.12.47-1+rpt1"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.12.47-1+rpt1": {
            "linux_commit": "359f37f0faefb712add32a39f98751aea67d5c1f",
            "upstream_version": "6.12.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.12.50"
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-39965"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0baf92d0b1590b903c1f4ead75e61715e50e8146"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9fcedabaae0096f712bbb4ccca6a8538af1cd1c8"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a78e55776522373c446f18d5002a8de4b09e6bf7"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/cd8ae32e4e4652db55bce6b9c79267d8946765a9"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T12:19:11Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The vulnerability is reached through the XFRM_MSG_ALLOCSPI message on a NETLINK_XFRM socket, which requires local system access. Although the dangling byspi entry can subsequently be dereferenced by a received ESP/AH packet, creating the SPI-0 state requires the local netlink path.\nAC:L - The attacker deterministically triggers the bug by requesting min=max=0, which verify_spi_info() accepts, then deleting the state via DELSA/FLUSHSA; there is no race, no memory-layout dependency, and no non-default config beyond ubiquitous CONFIG_XFRM_USER.\nPR:L - xfrm_user_rcv_msg() gates on netlink_net_capable(skb, CAP_NET_ADMIN), which is evaluated against the net namespace's user_ns, so any unprivileged user obtains it via \"unshare -Urn\". This is Low, not High.\nUI:N - The full sequence \u2014 allocate SPI 0, delete the state, re-walk the byspi hash \u2014 is performed entirely by the attacker's own process with no victim action required.\nS:U - The freed xfrm_state and the corrupted hash list both live in the kernel's own security authority; this is standard kernel memory corruption with no VM, IOMMU, or hypervisor boundary crossed.\nC:H - The dangling xfrm_state remains in a global RCU hash and is read back and returned as a live SA, so a reclaimed object leaks adjacent heap contents and crypto/key state, and the UAF can be escalated into an arbitrary kernel read primitive.\nI:H - Walkers perform refcount_inc_not_zero on the freed object (a write to freed memory) and then use it as a live SA whose type/mode function-pointer fields the attacker can control by re-spraying the xfrm_state slab, yielding control-flow hijack and arbitrary write.\nA:H - Dereferencing the freed state during byspi traversal, hash resize, or netns teardown (WARN_ON(!hlist_empty())) reliably produces a KASAN-detected use-after-free, list corruption, and kernel panic."
    }
  }
}