{"api_version":"1","generated_at":"2026-08-22T17:47:27+00:00","cve":"CVE-2026-74636","urls":{"html":"https://cve.report/CVE-2026-74636","api":"https://cve.report/api/cve/CVE-2026-74636.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74636","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74636"},"summary":{"title":"tracing: Fix race between update_event_fields and, event_define_fields","description":"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(&event_mutex)                   trace_event_update_all()\n         trace_module_add_events(A)                 down_write(&trace_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(&f->link,                                    &class->fields, link)\n                             &class->fields)            field = class->fields->next;\n\nWhere access to the class->fields 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.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-22 16:16:36","updated_at":"2026-08-22 16:16:36"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/4e39f7b4d9d36508c53e89e6cbc640728df870b5","name":"https://git.kernel.org/stable/c/4e39f7b4d9d36508c53e89e6cbc640728df870b5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/ed49684e69f846bf50b5050651ccdb87cfd152c0","name":"https://git.kernel.org/stable/c/ed49684e69f846bf50b5050651ccdb87cfd152c0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e5f1d301b4bdaa4206db251fdc691f623162b0a8","name":"https://git.kernel.org/stable/c/e5f1d301b4bdaa4206db251fdc691f623162b0a8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c3730b8373bb5059d735509b9e6a00d7eb337d7c","name":"https://git.kernel.org/stable/c/c3730b8373bb5059d735509b9e6a00d7eb337d7c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a30d421468300b1e7b2f233136aeb2db8013f555","name":"https://git.kernel.org/stable/c/a30d421468300b1e7b2f233136aeb2db8013f555","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/f128740f39ab28d1f4ad5bdd10f3e117eec0c374","name":"https://git.kernel.org/stable/c/f128740f39ab28d1f4ad5bdd10f3e117eec0c374","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/fdeb190b0905a6aaed1e5d6adfb8613214748d7d","name":"https://git.kernel.org/stable/c/fdeb190b0905a6aaed1e5d6adfb8613214748d7d","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74636","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74636","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7c6bd60999f32138e3b73fd97ea11ef47a94de25 4e39f7b4d9d36508c53e89e6cbc640728df870b5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b3bc8547d3be60898818885f5bf22d0a62e2eb48 a30d421468300b1e7b2f233136aeb2db8013f555 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b3bc8547d3be60898818885f5bf22d0a62e2eb48 e5f1d301b4bdaa4206db251fdc691f623162b0a8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b3bc8547d3be60898818885f5bf22d0a62e2eb48 fdeb190b0905a6aaed1e5d6adfb8613214748d7d git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b3bc8547d3be60898818885f5bf22d0a62e2eb48 ed49684e69f846bf50b5050651ccdb87cfd152c0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b3bc8547d3be60898818885f5bf22d0a62e2eb48 f128740f39ab28d1f4ad5bdd10f3e117eec0c374 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected b3bc8547d3be60898818885f5bf22d0a62e2eb48 c3730b8373bb5059d735509b9e6a00d7eb337d7c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 55defdf935fab9f2989a197aae1042c082d9a343 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 0c53a5c80e6e286733381a1d9f255ba4039e2e45 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.15.33 5.15.216 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.16.19 5.17 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.17.2 5.18 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.18","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.18 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.216 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.183 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.152 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.104 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.45 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.9 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"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"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.216","versionStartIncluding":"5.15.33","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.183","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.152","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.104","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.45","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.9","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"5.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17.2","vulnerable":true}],"negate":false,"operator":"OR"}]}],"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(&event_mutex)                   trace_event_update_all()\n         trace_module_add_events(A)                 down_write(&trace_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(&f->link,                                    &class->fields, link)\n                             &class->fields)            field = class->fields->next;\n\nWhere access to the class->fields 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."}],"providerMetadata":{"dateUpdated":"2026-08-22T15:32:16.026Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/4e39f7b4d9d36508c53e89e6cbc640728df870b5"},{"url":"https://git.kernel.org/stable/c/a30d421468300b1e7b2f233136aeb2db8013f555"},{"url":"https://git.kernel.org/stable/c/e5f1d301b4bdaa4206db251fdc691f623162b0a8"},{"url":"https://git.kernel.org/stable/c/fdeb190b0905a6aaed1e5d6adfb8613214748d7d"},{"url":"https://git.kernel.org/stable/c/ed49684e69f846bf50b5050651ccdb87cfd152c0"},{"url":"https://git.kernel.org/stable/c/f128740f39ab28d1f4ad5bdd10f3e117eec0c374"},{"url":"https://git.kernel.org/stable/c/c3730b8373bb5059d735509b9e6a00d7eb337d7c"}],"title":"tracing: Fix race between update_event_fields and, event_define_fields","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74636","datePublished":"2026-08-22T15:32:16.026Z","dateReserved":"2026-08-15T05:44:03.922Z","dateUpdated":"2026-08-22T15:32:16.026Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-22 16:16:36","lastModifiedDate":"2026-08-22 16:16:36","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74636","Ordinal":"1","Title":"tracing: Fix race between update_event_fields and, event_define_","CVE":"CVE-2026-74636","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74636","Ordinal":"1","NoteData":"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(&event_mutex)                   trace_event_update_all()\n         trace_module_add_events(A)                 down_write(&trace_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(&f->link,                                    &class->fields, link)\n                             &class->fields)            field = class->fields->next;\n\nWhere access to the class->fields 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.","Type":"Description","Title":"tracing: Fix race between update_event_fields and, event_define_"}]}}}