Vulnerability in Linux kernel (CVE-2026-74638)
Summary
Vulnerability in Linux kernel (CVE-2026-74638). Risk of unauthorized operations or information disclosure. Exploitable via reset_lock.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
drm/v3d: Serialize the scheduler timeout handlers
V3D exposes several independent hardware queues (BIN, RENDER, TFU and
CSD) but has only a single, global reset. A timeout on any one queue
therefore has to stop, reset and restart the schedulers of every other
queue as well. That makes concurrent timeout handlers unsafe.
reset_lock was never able to make them safe, as a driver-side lock can
only cover the driver's &drm_sched_backend_ops.timedout_job callback.
The scheduler handles the timed out job and its pending list around that
callback, outside of the driver's control, so a global reset triggered
by one queue can still interfere with another queue that is in the
middle of handling a timeout of its own.
Consequently, if a reset happens in the CSD queue while a CL-intensive
application is running, the global reset stops and restarts the CL
queue's scheduler while that queue is handling a timeout of its own. As
drm_sched_stop() and drm_sched_start() subtract and add the credits of
every job sitting on the pending list of the scheduler they are called
on, and as the CL queue's handler concurrently takes its job off that
same list and puts it back, the stop and the start no longer see the
same set of jobs. The CL queue is left with more credits in flight than
its limit:
[ 327.302739] ------------[ cut here ]------------
[ 327.302744] WARNING: CPU: 2 PID: 43 at drivers/gpu/drm/scheduler/sched_main.c:102…
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-74638 has been found in Linux kernel.
Attackers can target a specific entry point like reset_lock over the network to misuse the product.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2026-74638" on the vendor's site.
CVE-2026-74638 (Linux kernel)
Attack surface: reset_lock
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (unclassified) exists in Linux kernel. Attackers reach the vulnerable code path via reset_lock.
Check the vendor advisory for the affected versions of Linux kernel. Attack surface: reset_lock.
Severity: ?. Risk of unauthorized operations or information disclosure.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2026-74638 linux-lts
- Debian DEBIAN-CVE-2026-74638 linux
- Ubuntu UBUNTU-CVE-2026-74638 linux-hwe-edge
References
- advisory nvd.nist.gov
- advisory github.com
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web github.com