{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "0d345996e4cb573f8cc81d49b3ee9a7fd2035bef"
            },
            {
              "fixed": "0e96cd314c0d819c1635d68125a4d77852c2162e"
            },
            {
              "fixed": "593d67032544b9271094fc9b43e437e017cb2b2f"
            },
            {
              "fixed": "1e3e98596c2769721ade0418434852fb3af4849a"
            },
            {
              "fixed": "de05c66fab8847237a9ca216934e56d3ee837f08"
            },
            {
              "fixed": "917e3ad3321e75ca0223d5ccf26ceda116aa51e1"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "6.6.0"
            },
            {
              "fixed": "6.6.143"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.93"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.22"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "6.19.12"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43331.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/kexec: Disable KCOV instrumentation after load_segments()\n\nThe load_segments() function changes segment registers, invalidating GS base\n(which KCOV relies on for per-cpu data). When CONFIG_KCOV is enabled, any\nsubsequent instrumented C code call (e.g. native_gdt_invalidate()) begins\ncrashing the kernel in an endless loop.\n\nTo reproduce the problem, it's sufficient to do kexec on a KCOV-instrumented\nkernel:\n\n  $ kexec -l /boot/otherKernel\n  $ kexec -e\n\nThe real-world context for this problem is enabling crash dump collection in\nsyzkaller. For this, the tool loads a panic kernel before fuzzing and then\ncalls makedumpfile after the panic. This workflow requires both CONFIG_KEXEC\nand CONFIG_KCOV to be enabled simultaneously.\n\nAdding safeguards directly to the KCOV fast-path (__sanitizer_cov_trace_pc())\nis also undesirable as it would introduce an extra performance overhead.\n\nDisabling instrumentation for the individual functions would be too fragile,\nso disable KCOV instrumentation for the entire machine_kexec_64.c and\nphysaddr.c. If coverage-guided fuzzing ever needs these components in the\nfuture, other approaches should be considered.\n\nThe problem is not relevant for 32 bit kernels as CONFIG_KCOV is not supported\nthere.\n\n  [ bp: Space out comment for better readability. ]",
  "id": "CVE-2026-43331",
  "modified": "2026-07-15T01:48:54.901186573Z",
  "published": "2026-05-08T13:31:18.787Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0e96cd314c0d819c1635d68125a4d77852c2162e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1e3e98596c2769721ade0418434852fb3af4849a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/593d67032544b9271094fc9b43e437e017cb2b2f"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/917e3ad3321e75ca0223d5ccf26ceda116aa51e1"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de05c66fab8847237a9ca216934e56d3ee837f08"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43331.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43331"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.8.0",
  "summary": "x86/kexec: Disable KCOV instrumentation after load_segments()"
}