{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-80555",
  "modified": "2026-10-09T11:39:44Z",
  "upstream": [
    "CVE-2026-80555"
  ],
  "published": "2026-08-26T14:37:59Z",
  "summary": "s390/vfio_ccw: Free all memory if cp_init() fails",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/vfio_ccw: Free all memory if cp_init() fails\n\nThe routine cp_free() is called to unpin/free any memory once an I/O\nis completed successfully, or if cp_prefetch() fails. But if cp_init()\nfails, and cp->initialized is not enabled, the same routine cannot be\nused to free all the memory.\n\nAn attempt to address this exists in ccwchain_handle_ccw(), where a\nsingle call to ccwchain_free() is made for the currently-processed\nCCW segment. But this will leak other segments (created as a result\nof a Transfer in Channel) that had been allocated as part of the same\nchannel program.\n\nAddress this by performing the cleanup outside of the recursive\nccwchain_handle_ccw()/ccwchain_loop_tic() logic.",
  "severity": [
    {
      "type": "CVSS_V3",
      "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/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": "6.1.185",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-80555"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/276bd7ed34d56c48c65c43c0b08f2ee77029b2fa"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/f9bcff265556796834122f95de16d52a8375206c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/17e01e342af74de12899c206dcc9ec90684703aa"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/152fcb74a26804b70909381c6acc90595a0ae1c1"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6a917199aaf97904f5619afe3dfdacb155b03e8c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/32e3d364a7b8295120d37e6a6bd433d2de26f748"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/4699b54fada156534cbb39834d47fc9374d7a1f5"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/74186c2968f8f756ac3226b545b598457c910c75"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-08-27T12:40:42Z",
    "severity": {
      "source": "kernel CNA",
      "cvss_v3_score": 7.1,
      "cvss_v3_severity": "High",
      "scenario": "AV:L - The bug is reached when userspace writes the vfio-ccw io_region (VFIO device mmap/write), triggering fsm_io_request() -> cp_init(); on s390 KVM this is driven by QEMU forwarding guest channel-I/O channel programs, requiring local VFIO/device interaction rather than any network protocol.\nAC:L - An attacker can deterministically fail cp_init() after allocating multiple TIC-linked ccwchain segments by crafting a channel program whose early TIC targets succeed and a later one fails (invalid CPA, chain-length/count limit, or dma_rw error), leaking prior segments on every attempt without races.\nPR:N - On s390 KVM with CCW passthrough, a malicious guest can submit crafted multi-TIC channel programs through normal guest I/O; QEMU forwards them to vfio-ccw without the attacker holding host CAP_SYS_ADMIN, root, or other real init-namespace privileges beyond the assigned device.\nUI:N - No victim interaction is required beyond the attacker (or their guest) issuing channel-I/O start requests with a malicious channel program; exploitation does not depend on another user mounting media, accepting prompts, or performing administrative actions at trigger time.\nS:C - The leaked ccwchain, CCW, and page_array allocations are host kernel slab memory; a guest VM triggering this through passthrough crosses the guest-host virtualization boundary by consuming host resources the guest security domain should not affect.\nC:N - This is a kernel memory leak on the cp_init() error path, not a use-after-free, out-of-bounds read, or other memory corruption; leaked objects are orphaned in kernel heap and are not returned to userspace or the guest, so no information disclosure occurs.\nI:N - The flaw only fails to free kernel allocations when cp_init() errors; it does not corrupt memory, modify guest or host data, or provide write or control-flow primitives, and cp->initialized stays false so cp_free() never runs on the error or close paths.\nA:H - Each failed cp_init() permanently orphans up to CCWCHAIN_COUNT_MAX ccwchain segments (large GFP_DMA allocations), and subsequent cp_init() calls INIT_LIST_HEAD without freeing prior leaks; repeated guest or VFIO I/O requests can exhaust host memory and cause system-wide OOM or severe denial of service."
    }
  }
}