{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2025-38514",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2025-38514"
  ],
  "published": "2025-08-16T10:58:18Z",
  "summary": "rxrpc: Fix oops due to non-existence of prealloc backlog struct",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: Fix oops due to non-existence of prealloc backlog struct\n\nIf an AF_RXRPC service socket is opened and bound, but calls are\npreallocated, then rxrpc_alloc_incoming_call() will oops because the\nrxrpc_backlog struct doesn't get allocated until the first preallocation is\nmade.\n\nFix this by returning NULL from rxrpc_alloc_incoming_call() if there is no\nbacklog struct.  This will cause the incoming call to be aborted.",
  "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": "6.1.146",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-38514"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/bf0ca6a1bc4fb904b598137c6718785a107e3adf"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f7afb3ff01c42c49e8a143cdce400b95844bb506"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f5e72b7824d08c206ce106d30cb37c4642900ccc"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0eef29385d715d4c7fd707b18d4a9b76c76dd5e6"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/efc1b2b7c1a308b60df8f36bc2d7ce16d3999364"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d1ff5f9d2c5405681457262e23c720b08977c11f"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/2c2e9ebeb036f9b1b09325ec5cfdfe0e78f357c3"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/880a88f318cf1d2a0f4c0a7ff7b07e2062b434a4"
    }
  ],
  "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 oops is driven entirely by a received UDP/rxrpc datagram processed in the endpoint's I/O thread (`rxrpc_encap_rcv` \u2192 `rxrpc_input_packet` \u2192 `rxrpc_new_incoming_call`), and AF_RXRPC services live on routable UDP ports such as the well-known AFS callback port 7001. Any remote host able to send a packet to that port reaches the vulnerable function.\nAC:L - A single well-formed rxrpc DATA packet (seq!=0, callNumber!=0, matching serviceId, securityIndex 0) deterministically dereferences the NULL backlog pointer \u2014 no race, memory-layout, or timing dependency in the packet path itself, and the well-known service IDs are protocol constants. The attacker can simply keep the port fed so any bind\u2192listen window (as in `afs_open_socket`) is hit, and sockets bound without listening are persistently exposed.\nPR:N - The attacker is an unauthenticated remote peer holding no credentials on the victim: `rxrpc_get_incoming_security()` accepts `RXRPC_SECURITY_NONE` with no key at all, and even for secured services the CHALLENGE is only queued after `rxrpc_alloc_incoming_call()` has already crashed. The same crash is also reachable by a plain unprivileged local user, since `rxrpc_create()`/`rxrpc_bind()` require no capability.\nUI:N - The crash happens autonomously inside the rxrpc I/O kernel thread while processing an inbound packet against an already-bound service socket. No victim action, mount, or file access is part of the attack.\nS:U - The NULL dereference and its consequences are confined to the kernel of the host running the AF_RXRPC service socket, with no crossing into a hypervisor, IOMMU, or sandbox authority.\nC:N - The faulting access is a read of `b->call_backlog_head` at offset 4 from NULL, which is below `mmap_min_addr` and faults immediately. No kernel memory contents are returned to the attacker or leaked to userspace.\nI:N - Execution aborts on the very first load in `rxrpc_alloc_incoming_call()`, before any of the subsequent stores (`peer->srx = *peer_srx`, `conn->local = ...`) are reached. Nothing is written or corrupted, so no overwrite or control-flow hijack primitive exists.\nA:H - The dereference oopses the rxrpc I/O kthread while it holds `read_lock_irq(&local->services_lock)` and `spin_lock(&rx->incoming_lock)`, so the thread dies with IRQs disabled and both locks permanently held \u2014 all rxrpc/AFS traffic on that endpoint stops and any later bind or socket release spins forever. Under the common `panic_on_oops=1` configuration it is an immediate full system panic, repeatable with one packet."
    }
  }
}