{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2024-47748",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2024-47748"
  ],
  "published": "2024-10-21T12:16:24Z",
  "summary": "vhost_vdpa: assign irq bypass producer token correctly",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost_vdpa: assign irq bypass producer token correctly\n\nWe used to call irq_bypass_unregister_producer() in\nvhost_vdpa_setup_vq_irq() which is problematic as we don't know if the\ntoken pointer is still valid or not.\n\nActually, we use the eventfd_ctx as the token so the life cycle of the\ntoken should be bound to the VHOST_SET_VRING_CALL instead of\nvhost_vdpa_setup_vq_irq() which could be called by set_status().\n\nFixing this by setting up irq bypass producer's token when handling\nVHOST_SET_VRING_CALL and un-registering the producer before calling\nvhost_vring_ioctl() to prevent a possible use after free as eventfd\ncould have been released in vhost_vring_ioctl(). And such registering\nand unregistering will only be done if DRIVER_OK is set.",
  "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": [
        "1:6.1.47-1+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": "6.1.113",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2024-47748"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/0c170b1e918b9afac25e2bbd01eaa2bfc0ece8c0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/927a2580208e0f9b0b47b08f1c802b7233a7ba3c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ec5f1b54ceb23475049ada6e7a43452cf4df88d1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/ca64edd7ae93402af2596a952e0d94d545e2b9c0"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/fae9b1776f53aab93ab345bdbf653b991aed717d"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/7cf2fb51175cafe01df8c43fa15a06194a59c6e2"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/02e9e9366fefe461719da5d173385b6685f70319"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-05T11:52:36Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.8,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The vulnerability is reached exclusively through `ioctl()` calls (`VHOST_SET_VRING_CALL`, `VHOST_VDPA_SET_STATUS`) on the `/dev/vhost-vdpa-N` character device. This requires local access to the host; no network or adjacent-network path exists.\nAC:L - The attacker deterministically drives the entire sequence with ordinary ioctls \u2014 set a call fd, set DRIVER_OK, reset to invalidate the MSI vector, then rebind a new call fd \u2014 and controls both the eventfd allocation and the eventfd free, so the slab reuse that makes the stale token collide is attacker-driven grooming rather than an uncontrolled condition. No race with an independent party is involved.\nPR:L - No capability check exists anywhere on the path; the sole gate is DAC on the vhost-vdpa device node, which in the standard libvirt/QEMU hypervisor deployment is held by an unprivileged VMM account. An attacker with that account \u2014 or one who has compromised the QEMU process from a guest \u2014 reaches the bug without root.\nUI:N - The attacker performs the complete ioctl sequence and eventfd grooming from their own process. No action by any other user or administrator is needed.\nS:U - The vulnerable component and the primary impacted component are both the host kernel, so the memory corruption stays within a single security authority. The knock-on effect on other guests' interrupt-remapping entries is a consequence of host-kernel compromise rather than an exploit that crosses the boundary as its defining characteristic.\nC:H - The freed eventfd_ctx pointer is retained as an identity key in a global registry shared with KVM, and the resulting mismatched connect/disconnect plus irqbypass module refcount underflow give the attacker use-after-free access to kernel objects and module memory. Per standard kernel scoring, a use-after-free grants control over freed-object contents and is treated as enabling arbitrary kernel memory disclosure.\nI:H - The stale token causes `__disconnect()`/`__connect()` against the wrong consumer, reprogramming IOMMU interrupt-remapping entries for an unrelated VM with a foreign device IRQ, while the double `list_del()` on an already-unlinked node provides a linked-list unlink write primitive and the module refcount underflow enables a UAF on module text. These are exploitable for kernel memory corruption and control-flow hijacking.\nA:H - Executing `list_del()` on a node bearing `LIST_POISON1/LIST_POISON2` faults immediately with a general protection fault, and the mismatched KVM producer teardown trips `WARN_ON` and corrupts posted-interrupt state. This is a reliable kernel oops/panic that also disrupts unrelated guests on the host."
    }
  }
}