CVE-2026-74636
Full vulnerability record from the local CVENow database.
Description
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.
Severity
Not scored
CVSS score
Not available
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-22 16:16:36.750000
Last modified
2026-11-06 17:19:52.173000
View original CVE JSON
{
"id": "CVE-2026-74636",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-22T16:16:36.750",
"lastModified": "2026-11-06T17:19:52.173",
"vulnStatus": "Received",
"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(&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."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\ntracing: Solucionar condición de carrera entre update_event_fields y event_define_fields\n\nLa siguiente secuencia puede provocar una condición de carrera entre event_define_fields() y update_event_fields():\n\n CPU0 (carga el módulo A) CPU1 (carga el módulo 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 para cada f: list_for_each_entry(field,\n list_add(&f -> link, &class -> fields, link)\n &class -> fields) field = class -> fields -> next;\n\nDonde el acceso a class -> fields no está protegido por el event_mutex en trace_event_update_all().\n\nEsto produce el siguiente pánico:\n No se puede manejar el acceso al kernel ... en la dirección virtual 0000000000000018\n pc : update_event_fields+0xf8/0x368\n Rastro de llamada:\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\nSolución al tomar event_mutex en trace_event_update_all() antes de trace_event_sem."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"kernel/trace/trace_events.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "7c6bd60999f32138e3b73fd97ea11ef47a94de25",
"lessThan": "4e39f7b4d9d36508c53e89e6cbc640728df870b5",
"versionType": "git",
"status": "affected"
},
{
"version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
"lessThan": "a30d421468300b1e7b2f233136aeb2db8013f555",
"versionType": "git",
"status": "affected"
},
{
"version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
"lessThan": "e5f1d301b4bdaa4206db251fdc691f623162b0a8",
"versionType": "git",
"status": "affected"
},
{
"version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
"lessThan": "fdeb190b0905a6aaed1e5d6adfb8613214748d7d",
"versionType": "git",
"status": "affected"
},
{
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"lessThan": "ed49684e69f846bf50b5050651ccdb87cfd152c0",
"versionType": "git",
"status": "affected"
},
{
"version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
"lessThan": "f128740f39ab28d1f4ad5bdd10f3e117eec0c374",
"versionType": "git",
"status": "affected"
},
{
"version": "b3bc8547d3be60898818885f5bf22d0a62e2eb48",
"lessThan": "c3730b8373bb5059d735509b9e6a00d7eb337d7c",
"versionType": "git",
"status": "affected"
},
{
"version": "55defdf935fab9f2989a197aae1042c082d9a343",
"versionType": "git",
"status": "affected"
},
{
"version": "0c53a5c80e6e286733381a1d9f255ba4039e2e45",
"versionType": "git",
"status": "affected"
},
{
"version": "5.15.33",
"lessThan": "5.15.216",
"versionType": "semver",
"status": "affected"
},
{
"version": "5.16.19",
"lessThan": "5.17",
"versionType": "semver",
"status": "affected"
},
{
"version": "5.17.2",
"lessThan": "5.18",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"kernel/trace/trace_events.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "5.18",
"status": "affected"
},
{
"version": "0",
"lessThan": "5.18",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.216",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.183",
"lessThanOrEqual": "6.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.152",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.104",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.45",
"lessThanOrEqual": "6.18.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1.9",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-11-06T17:00:17.420037Z",
"id": "CVE-2026-74636",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
{
"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",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}