{
  "schema_version": "1.6.1",
  "id": "RPI-CVE-2026-89923",
  "modified": "2026-10-07T17:22:01Z",
  "upstream": [
    "CVE-2026-89923"
  ],
  "published": "2026-09-16T10:32:03Z",
  "summary": "KVM: s390: Free guest debug data on vcpu destroy",
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Free guest debug data on vcpu destroy\n\nkvm_s390_clear_bp_data() is only called from\nkvm_arch_vcpu_ioctl_set_guest_debug(), i.e. when user space changes or\ndisables debugging. A vCPU that is destroyed while hardware breakpoints\nare still armed - the normal case when the VMM just exits or crashes -\nleaks hw_bp_info, hw_wp_info and all old_data buffers, since generic KVM\nfrees the vCPU right after kvm_arch_vcpu_destroy().\n\nThat is bounded by MAX_BP_COUNT entries, so roughly 8 KiB per vCPU, but\nit is unbounded over VM lifetimes. The allocations are\nGFP_KERNEL_ACCOUNT, so the charge also outlives the exiting process and\npins dying memcgs.\n\nFix by clearing the debug data on vCPU destruction. Calling it\nunconditionally is fine: struct kvm_vcpu is zero allocated, so for a vCPU\nthat never enabled debugging the counters are 0 and the pointers NULL.",
  "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": "6.1.188",
            "compiled_filter": false
          }
        }
      }
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-89923"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/053f2068cf9b0654b651fed5ad7649d3deb982bf"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/6c996b12bbe4a6023076e8eee3cfaf2cc99db76c"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/d6280fc540d8f4653c9b54a78cb747e128070f5e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/544a5a665019cef394ce8bda97fa7a2cab253781"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/b5acacfdb8966abff91836c1c5bd7da59d8a526e"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e4d8b7f176b976474e0800ba71ee2dfa3ce263c9"
    },
    {
      "type": "FIX",
      "url": "https://git.kernel.org/stable/c/e7f698b09d4a7c36b299acf680fc50fe868e2bcd"
    }
  ],
  "database_specific": {
    "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git",
    "upstream_modified": "2026-09-16T10:32:03Z"
  }
}