Linux Kernel up to 7.1.8 tracing trace_event_update_all locking

CVSS Meta Temp Score
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CTI Interest Score
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8.7$0-$5k0.87

Summaryinfo

A vulnerability classified as very critical has been found in Linux Kernel up to 7.1.8. Impacted is the function trace_event_update_all of the component tracing. The manipulation leads to locking. This vulnerability is documented as CVE-2026-74636. The attack can be initiated remotely. There is not any exploit available.

Detailsinfo

A vulnerability was found in Linux Kernel up to 7.1.8 and classified as very critical. This issue affects the function trace_event_update_all of the component tracing. The manipulation with an unknown input leads to a locking vulnerability. Using CWE to declare the problem leads to CWE-667. The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2026-74636 since 08/15/2026. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation needs additional levels of successful authentication. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/22/2026).

Upgrading to version 5.15.216, 6.1.183, 6.6.152, 6.12.104, 6.18.45 or 7.1.9 eliminates this vulnerability. Applying the patch 4e39f7b4d9d36508c53e89e6cbc640728df870b5/a30d421468300b1e7b2f233136aeb2db8013f555/e5f1d301b4bdaa4206db251fdc691f623162b0a8/fdeb190b0905a6aaed1e5d6adfb8613214748d7d/ed49684e69f846bf50b5050651ccdb87cfd152c0/f128740f39ab28d1f4ad5bdd10f3e117eec0c374/c3730b8373bb5059d735509b9e6a00d7eb337d7c is able to eliminate this problem.

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 9.1
VulDB Meta Temp Score: 8.7

VulDB Base Score: 9.1
VulDB Temp Score: 8.7
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Locking
CWE: CWE-667
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.216/6.1.183/6.6.152/6.12.104/6.18.45/7.1.9
Patch: 4e39f7b4d9d36508c53e89e6cbc640728df870b5/a30d421468300b1e7b2f233136aeb2db8013f555/e5f1d301b4bdaa4206db251fdc691f623162b0a8/fdeb190b0905a6aaed1e5d6adfb8613214748d7d/ed49684e69f846bf50b5050651ccdb87cfd152c0/f128740f39ab28d1f4ad5bdd10f3e117eec0c374/c3730b8373bb5059d735509b9e6a00d7eb337d7c

Timelineinfo

08/15/2026 CVE reserved
08/22/2026 +7 days Advisory disclosed
08/22/2026 +0 days VulDB entry created
08/22/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-74636 (🔒)
GCVE (CVE): GCVE-0-2026-74636
GCVE (VulDB): GCVE-100-394421

Entryinfo

Created: 08/22/2026 18:31
Changes: 08/22/2026 18:31 (59)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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