{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2026-64451",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-64451",
    "idYear": 2026,
    "status": "PUBLISHED",
    "publishedAt": "2026-07-25T08:51:21.020Z",
    "updatedAt": "2026-08-17T04:55:55.128Z",
    "importedAt": "2026-10-24T01:58:25.636Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "tracing: Fix NULL pointer dereference in func_set_flag()",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix NULL pointer dereference in func_set_flag()\n\nfunc_set_flag() dereferences tr->current_trace_flags before verifying\nthat the current tracer is actually the function tracer. When the active\ntracer has been switched away from \"function\" (e.g., to \"wakeup_rt\"),\ntr->current_trace_flags can be NULL, leading to a NULL pointer\ndereference and kernel crash.\n\nThe call chain that triggers this is:\n\n  trace_options_write()\n    -> __set_tracer_option()\n      -> trace->set_flag()          /* func_set_flag */\n\nIn func_set_flag(), the first operation is:\n\n  if (!!set == !!(tr->current_trace_flags->val & bit))\n\nThis dereferences tr->current_trace_flags unconditionally. The safety\ncheck that guards against a non-function tracer:\n\n  if (tr->current_trace != &function_trace)\n      return 0;\n\nis placed *after* the dereference, which is too late.\n\nThis was observed with the following crash dump:\n\n  BUG: unable to handle page fault at 0000000000000000\n  RIP: func_set_flag+0xd\n\n  Call Trace:\n   __set_tracer_option+0x27\n   trace_options_write+0x75\n   vfs_write+0x12a\n   ksys_write+0x66\n   do_syscall_64+0x5b\n\n  RIP: ffffffff914c973d  RSP: ff67ec88b01dfdf0  RFLAGS: 00010202\n  RAX: 0000000000000000  RBX: ff3a826e80354580  RCX: 0000000000000001\n  RDX: 0000000000000001  RSI: 0000000000000000  RDI: ffffffff93918080\n\nThe disassembly confirms the fault:\n\n  func_set_flag+0:   mov 0x1f08(%rdi), %rax  ; RAX = tr->current_trace_flags = NULL\n  func_set_flag+13:  mov (%rax), %eax        ; page fault: dereference NULL\n\nAt the time of the crash:\n  tr->current_trace_flags = 0x0 (NULL)\n  tr->current_trace = wakeup_rt_tracer (not function_trace)\n\nThe scenario is that a process opens a function tracer option file (such\nas \"func_stack_trace\"), then the current tracer is switched to another\ntracer (e.g., \"wakeup_rt\"), which sets current_trace_flags to NULL. When\nthe process subsequently writes to the option file, func_set_flag() is\ninvoked and crashes on the NULL dereference.\n\nFix this by moving the current_trace check before the\ncurrent_trace_flags dereference, so that func_set_flag() returns early\nwhen the function tracer is not active.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "76680d0d2825900f23bf35290ab2b80bdf3a8e4a",
              "status": "affected",
              "versionType": "git",
              "lessThan": "69f17ac132a38974cf1defb480cef6b79d1ab768"
            },
            {
              "version": "76680d0d2825900f23bf35290ab2b80bdf3a8e4a",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c3e94604675e3db186111b8942650d86577df9b0"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.19",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.19"
            },
            {
              "version": "7.1.4",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "version": "7.2",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}