drm/amdkfd: hold event_mutex while checkpointing CRIU events
Why It Matters
Analysis dossierWhy It Matters
In the Linux kernel, the following vulnerability has been resolved: drm/amdkfd: hold event_mutex while checkpointing CRIU events kfd_criu_checkpoint_events() counts the entries in p->event_idr via kfd_get_num_events(), allocates an array sized to that count, and then walks the same IDR to fill it. Neither the count nor the walk holds p->event_mutex. The CRIU checkpoint caller holds only p->mutex. Event create and destroy (kfd_event_create()/kfd_event_destroy()) take p->event_mutex and do not take p->mutex, so a second thread in the same process can insert or remove events between the count and the walk. If an event is inserted, the walk iterates more entries than were counted and writes past the end of the ev_privs allocation; if an event is removed, the walk dereferences an entry that is being freed. Hold p->event_mutex across the count and the walk so both observe a consistent view of p->event_idr. The lock is released before copy_to_user(), which only touches the local buffer. The caller already holds p->mutex and the create/destroy paths never take p->mutex, so the p->mutex -> p->event_mutex order is not inverted and no deadlock is introduced. (cherry picked from commit ff57e223ab105795b05d3ef3f3c35a5a441bcbaa)
High
Unknown
Unknown
Risk basis: SOC ecosystem technology relevance; HIGH severity; No confirmed exploitation signal in current enrichment
Affected Products & Remediation
1 source-backed product- azl3 kernel 6.6.150.1-1 on Azure Linux 3.0 · version range not provided by source · Microsoft MSRC · Source
Vendor or catalog guidance (source)
- Microsoft MSRC: Release Notes
Known exploitation (source facts)
Only what a source states. Unknown means no source has said either way; it is not "not exploited".
- CISA KEV
- Unknown
- Exploited (source statement)
- Unknown
- Publicly disclosed (source)
- Unknown
Suggested hunting (rule-based inference)
SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.
Matched local-privilege-escalation (CVSS AV:L, CVSS PR:L)
Exposure
- Identify hosts reporting this CVE, prioritising shared or multi-user systems.Telemetry: DeviceTvmSoftwareVulnerabilities · A local, low-privilege vector matters most where untrusted users can run code. · Rule local-privilege-escalation
Exploitation evidence
- Look for low-privileged processes spawning SYSTEM or root-level child processes on affected hosts.Telemetry: DeviceProcessEvents · Hunting hypothesis from the CVSS vector; privilege transitions are a focused starting point, not evidence of attack. · Rule local-privilege-escalation
Response
- Confirm the source-stated update on affected hosts.Telemetry: DeviceTvmSoftwareVulnerabilities · Host inventory can verify remediation. · Rule local-privilege-escalation
CISA KEV Record
CISA KEV status was not determined for this record.
Change History & Source Data
— No recorded material change
- CNA / source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- Record status · verification
- UPDATED · NVD API
- CPE
- Unknown
Evidence & Provenance
Linked by the query's stored exact CVE association. Review required tables and validation status before use.
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2026-74446"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc