{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.0.12-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "In the Linux kernel, the following vulnerability has been resolved:  powerpc/hv-gpci: fix preempt count leak in sysfs show paths  Four sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_reqb) (which calls preempt_disable()) but only call the matching put_cpu_var() on the error path under the 'out:' label. Every successful read leaks one preempt_disable():    processor_bus_topology_show()   processor_config_show()   affinity_domain_via_virtual_processor_show()   affinity_domain_via_domain_show()  (affinity_domain_via_partition_show() was already correct.)  On a CONFIG_PREEMPT=y kernel, repeated reads raise preempt_count and eventually return to userspace with preemption still disabled. The next user-mode page fault then hits faulthandler_disabled() == 1, gets forced to SIGSEGV, and the resulting coredump trips 'BUG: scheduling while atomic' in call_usermodehelper_exec -\u003e wait_for_completion_state -\u003e schedule:    BUG: scheduling while atomic: \u003ctask\u003e/\u003cpid\u003e/0x00000004   ...   __schedule_bug+0x6c/0x90   __schedule+0x58c/0x13a0   schedule+0x48/0x1a0   schedule_timeout+0x104/0x170   wait_for_completion_state+0x16c/0x330   call_usermodehelper_exec+0x254/0x2d0   vfs_coredump+0x1050/0x2590   get_signal+0xb9c/0xc80   do_notify_resume+0xf8/0x470  Add an out_success label that calls put_cpu_var() before returning the byte count, mirroring affinity_domain_via_partition_show().",
  "id": "DEBIAN-CVE-2026-64070",
  "modified": "2026-09-14T16:47:40.125556540Z",
  "published": "2026-07-19T16:17:47.583Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-64070"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    }
  ],
  "upstream": [
    "CVE-2026-64070"
  ]
}