CVE-2026-74636 (GCVE-0-2026-74636)
Vulnerability from cvelistv5
Published
2026-08-22 15:32
Modified
2026-08-22 15:32
Severity ?
VLAI Severity ?
EPSS score ?
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
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: 7c6bd60999f32138e3b73fd97ea11ef47a94de25 Version: b3bc8547d3be60898818885f5bf22d0a62e2eb48 Version: b3bc8547d3be60898818885f5bf22d0a62e2eb48 Version: b3bc8547d3be60898818885f5bf22d0a62e2eb48 Version: b3bc8547d3be60898818885f5bf22d0a62e2eb48 Version: b3bc8547d3be60898818885f5bf22d0a62e2eb48 Version: b3bc8547d3be60898818885f5bf22d0a62e2eb48 Version: 55defdf935fab9f2989a197aae1042c082d9a343 Version: 0c53a5c80e6e286733381a1d9f255ba4039e2e45 Version: 5.15.33 ≤ Version: 5.16.19 ≤ Version: 5.17.2 ≤ |
||
{
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"cpeApplicability": [
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],
"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."
}
],
"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"
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{
"url": "https://git.kernel.org/stable/c/e5f1d301b4bdaa4206db251fdc691f623162b0a8"
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{
"url": "https://git.kernel.org/stable/c/fdeb190b0905a6aaed1e5d6adfb8613214748d7d"
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{
"url": "https://git.kernel.org/stable/c/ed49684e69f846bf50b5050651ccdb87cfd152c0"
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{
"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": {
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}
}
},
"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"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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