FKIE_CVE-2026-74636

Vulnerability from fkie_nvd - Published: 2026-08-22 16:16 - Updated: 2026-08-22 16:16
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: tracing: Fix race between update_event_fields and, event_define_fields The following sequence may leads race between event_define_fields() and update_event_fields(): CPU0 (loads module A) CPU1 (loads module B) =============================== =============================== load_module(A) load_module(B) notifier_call_chain notifier_call_chain trace_module_notify trace_module_notify mutex_lock(&event_mutex) trace_event_update_all() trace_module_add_events(A) down_write(&trace_event_sem) __register_event(call_A) __add_event_to_tracers(call_A) event_define_fields(call_A) for each f: list_for_each_entry(field, list_add(&f->link, &class->fields, link) &class->fields) field = class->fields->next; Where access to the class->fields is not protected by the event_mutex in trace_event_update_all(). This produces the following panic: Unable to handle kernel access ... at virtual address 0000000000000018 pc : update_event_fields+0xf8/0x368 Call trace: update_event_fields+0xf8/0x368 trace_event_update_all+0x7c/0x2b4 trace_module_notify+0x4c/0x1dc notifier_call_chain+0x84/0x168 blocking_notifier_call_chain_robust+0x64/0xd4 load_module+0x10c8/0x123c __arm64_sys_finit_module+0x230/0x31c Fix by taking event_mutex in trace_event_update_all() before trace_event_sem.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4e39f7b4d9d36508c53e89e6cbc640728df870b5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a30d421468300b1e7b2f233136aeb2db8013f555
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/c3730b8373bb5059d735509b9e6a00d7eb337d7c
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e5f1d301b4bdaa4206db251fdc691f623162b0a8
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ed49684e69f846bf50b5050651ccdb87cfd152c0
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/f128740f39ab28d1f4ad5bdd10f3e117eec0c374
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/fdeb190b0905a6aaed1e5d6adfb8613214748d7d
Impacted products
Vendor Product Version
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{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/trace_events.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "4e39f7b4d9d36508c53e89e6cbc640728df870b5",
              "status": "affected",
              "version": "7c6bd60999f32138e3b73fd97ea11ef47a94de25",
              "versionType": "git"
            },
            {
              "lessThan": "a30d421468300b1e7b2f233136aeb2db8013f555",
              "status": "affected",
              "version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
              "versionType": "git"
            },
            {
              "lessThan": "e5f1d301b4bdaa4206db251fdc691f623162b0a8",
              "status": "affected",
              "version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
              "versionType": "git"
            },
            {
              "lessThan": "fdeb190b0905a6aaed1e5d6adfb8613214748d7d",
              "status": "affected",
              "version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
              "versionType": "git"
            },
            {
              "lessThan": "ed49684e69f846bf50b5050651ccdb87cfd152c0",
              "status": "affected",
              "version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
              "versionType": "git"
            },
            {
              "lessThan": "f128740f39ab28d1f4ad5bdd10f3e117eec0c374",
              "status": "affected",
              "version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
              "versionType": "git"
            },
            {
              "lessThan": "c3730b8373bb5059d735509b9e6a00d7eb337d7c",
              "status": "affected",
              "version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "55defdf935fab9f2989a197aae1042c082d9a343",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "0c53a5c80e6e286733381a1d9f255ba4039e2e45",
              "versionType": "git"
            },
            {
              "lessThan": "5.15.216",
              "status": "affected",
              "version": "5.15.33",
              "versionType": "semver"
            },
            {
              "lessThan": "5.17",
              "status": "affected",
              "version": "5.16.19",
              "versionType": "semver"
            },
            {
              "lessThan": "5.18",
              "status": "affected",
              "version": "5.17.2",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/trace_events.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.18"
            },
            {
              "lessThan": "5.18",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.216",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.183",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.152",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.104",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.45",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.9",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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",
  "lastModified": "2026-08-22T16:16:36.750",
  "metrics": {},
  "published": "2026-08-22T16:16:36.750",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4e39f7b4d9d36508c53e89e6cbc640728df870b5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a30d421468300b1e7b2f233136aeb2db8013f555"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c3730b8373bb5059d735509b9e6a00d7eb337d7c"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e5f1d301b4bdaa4206db251fdc691f623162b0a8"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ed49684e69f846bf50b5050651ccdb87cfd152c0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/f128740f39ab28d1f4ad5bdd10f3e117eec0c374"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fdeb190b0905a6aaed1e5d6adfb8613214748d7d"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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