{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-38018",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2025-38018"
  ],
  "published": "2025-06-18T09:29:20Z",
  "summary": "net/tls: fix kernel panic when alloc_page failed",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tls: fix kernel panic when alloc_page failed\n\nWe cannot set frag_list to NULL pointer when alloc_page failed.\nIt will be used in tls_strp_check_queue_ok when the next time\ntls_strp_read_sock is called.\n\nThis is because we don't reset full_len in tls_strp_flush_anchor_copy()\nso the recv path will try to continue handling the partial record\non the next call but we dettached the rcvq from the frag list.\nAlternative fix would be to reset full_len.\n\nUnable to handle kernel NULL pointer dereference\nat virtual address 0000000000000028\n Call trace:\n tls_strp_check_rcv+0x128/0x27c\n tls_strp_data_ready+0x34/0x44\n tls_data_ready+0x3c/0x1f0\n tcp_data_ready+0x9c/0xe4\n tcp_data_queue+0xf6c/0x12d0\n tcp_rcv_established+0x52c/0x798",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
    }
  ],
  "affected": [
    {
      "package": {
        "ecosystem": "Raspberry Pi OS:12",
        "name": "linux"
      },
      "versions": [
        "1:6.1.47-1+rpt4"
      ],
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-2712",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v6",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l",
            "binary_version": "1:6.1.47-1+rpt4"
          },
          {
            "binary_name": "linux-image-6.1.0-rpi3-rpi-v8",
            "binary_version": "1:6.1.47-1+rpt4"
          }
        ]
      },
      "database_specific": {
        "per_version": {
          "1:6.1.47-1+rpt4": {
            "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e",
            "upstream_version": "6.1.47",
            "assessment": "commit ancestry (strak rule)",
            "upstream_fixed": "6.1.140",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-38018"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/8f7f96549bc55e4ef3a6b499bc5011e5de2f46c4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/406d05da26835943568e61bb751c569efae071d4"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/a11b8c0be6acd0505a58ff40d474bd778b25b93a"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/5f1f833cb388592bb46104463a1ec1b7c41975b6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/491deb9b8c4ad12fe51d554a69b8165b9ef9429f"
    }
  ],
  "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": 7.5,
      "cvss_v3_severity": "High",
      "scenario": "AV:N - The entire code path is driven by data received from the remote TLS peer \u2014 `tcp_rcv_established \u2192 tcp_data_queue \u2192 tcp_data_ready \u2192 tls_data_ready \u2192 tls_strp_data_ready \u2192 tls_strp_check_rcv \u2192 tls_strp_read_sock` \u2014 and the remote peer controls the TLS record framing and TCP segmentation that force the buggy `tls_strp_read_copy()` path. No local access is needed, matching the established kTLS scoring convention (CVE-2025-38471, CVE-2025-40176, CVE-2025-39946).\nAC:L - The attacker controls both required conditions: sending a TLS record header declaring a large payload followed by only a partial payload forces `inq < full_len` into `tls_strp_read_copy()`, and stalling the reader drives `tcp_rmem_pressure()` true so the allocation loop is entered \u2014 where `sk->sk_allocation` has been forced to `GFP_ATOMIC` by `tls_data_ready()`, making a 5-page order-0 failure readily inducible by spraying connections to exhaust atomic reserves. Repo precedent for allocation-failure NULL derefs (CVE-2025-40053) uses AC:L.\nPR:N - The strparser runs on every record received on a kTLS-RX socket, so any remote client that completes a standard server-authenticated TLS handshake with a kTLS-enabled server (nginx, HTTP/2, message brokers) can drive it without presenting any credentials to the target. No local account or capability is involved.\nUI:N - The crash is triggered entirely by the attacker's own packet stream arriving in the TCP receive softirq; no action by a local user or administrator is required.\nS:U - The NULL dereference occurs in kernel context and its effect is confined to the kernel of the affected host, crossing no VM, hypervisor, IOMMU, or other security-authority boundary.\nC:N - The fault is a dereference of a NULL `frag_list` at the fixed offset 0x28 (`TCP_SKB_CB(first)->seq`), a non-mappable low address under mmap_min_addr; no attacker-controlled data is read and nothing is copied back to userspace or the peer.\nI:N - No memory is written or corrupted \u2014 the stale anchor retains `len`/`data_len` with zero frags, which only makes `skb_copy_bits()` return `-EFAULT`, and the detached pointer is NULL rather than dangling, so there is no write or control-flow primitive.\nA:H - The NULL dereference occurs in softirq context inside `tcp_rcv_established()`, producing a fatal exception in interrupt that panics the machine (and guarantees reboot where `panic_on_oops` is set, as on Android and embedded builds), as reflected in the commit title \"fix kernel panic when alloc_page failed.\""
    }
  }
}