{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "7c6bd60999f32138e3b73fd97ea11ef47a94de25"
            },
            {
              "fixed": "4e39f7b4d9d36508c53e89e6cbc640728df870b5"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "b3bc8547d3be60898818885f5bf22d0a62e2eb48"
            },
            {
              "fixed": "a30d421468300b1e7b2f233136aeb2db8013f555"
            },
            {
              "fixed": "e5f1d301b4bdaa4206db251fdc691f623162b0a8"
            },
            {
              "fixed": "fdeb190b0905a6aaed1e5d6adfb8613214748d7d"
            },
            {
              "fixed": "ed49684e69f846bf50b5050651ccdb87cfd152c0"
            },
            {
              "fixed": "f128740f39ab28d1f4ad5bdd10f3e117eec0c374"
            },
            {
              "fixed": "c3730b8373bb5059d735509b9e6a00d7eb337d7c"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "55defdf935fab9f2989a197aae1042c082d9a343"
            },
            {
              "last_affected": "0c53a5c80e6e286733381a1d9f255ba4039e2e45"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.15.33"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.16.19"
            },
            {
              "fixed": "5.17"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "5.17.2"
            },
            {
              "fixed": "5.18"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "5.15.216"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.16.0"
            },
            {
              "fixed": "6.1.183"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "5.18.0"
            },
            {
              "fixed": "6.6.152"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.12.104"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.18.45"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "7.1.9"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74636.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Fix race between update_event_fields and, event_define_fields\n\nThe following sequence may leads race between event_define_fields()\nand update_event_fields():\n\n CPU0 (loads module A)                      CPU1 (loads module B)\n ===============================            ===============================\n load_module(A)                             load_module(B)\n   notifier_call_chain                        notifier_call_chain\n     trace_module_notify                        trace_module_notify\n       mutex_lock(\u0026event_mutex)                   trace_event_update_all()\n         trace_module_add_events(A)                 down_write(\u0026trace_event_sem)\n            __register_event(call_A)\n              __add_event_to_tracers(call_A)\n                event_define_fields(call_A)\n                  for each f:                         list_for_each_entry(field,\n                    list_add(\u0026f-\u003elink,                                    \u0026class-\u003efields, link)\n                             \u0026class-\u003efields)            field = class-\u003efields-\u003enext;\n\nWhere access to the class-\u003efields is not protected by the event_mutex in\ntrace_event_update_all().\n\nThis produces the following panic:\n   Unable to handle kernel access ... at virtual address 0000000000000018\n   pc : update_event_fields+0xf8/0x368\n   Call trace:\n    update_event_fields+0xf8/0x368\n    trace_event_update_all+0x7c/0x2b4\n    trace_module_notify+0x4c/0x1dc\n    notifier_call_chain+0x84/0x168\n    blocking_notifier_call_chain_robust+0x64/0xd4\n    load_module+0x10c8/0x123c\n    __arm64_sys_finit_module+0x230/0x31c\n\nFix by taking event_mutex in trace_event_update_all() before\ntrace_event_sem.",
  "id": "CVE-2026-74636",
  "modified": "2026-08-24T11:36:05.200090761Z",
  "published": "2026-08-22T15:32:16.026Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/4e39f7b4d9d36508c53e89e6cbc640728df870b5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a30d421468300b1e7b2f233136aeb2db8013f555"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c3730b8373bb5059d735509b9e6a00d7eb337d7c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e5f1d301b4bdaa4206db251fdc691f623162b0a8"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ed49684e69f846bf50b5050651ccdb87cfd152c0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f128740f39ab28d1f4ad5bdd10f3e117eec0c374"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fdeb190b0905a6aaed1e5d6adfb8613214748d7d"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74636.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74636"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "tracing: Fix race between update_event_fields and, event_define_fields"
}