LiveActive security incident?Get immediate response
CVE Record

CVE-2021-47273: usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled When only PHY1 is used (for example on Odroid-HC4), the regmap init code uses the usb2 ports when doesn't initialize the PHY1 regmap entry. This fixes: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000020 ... pc : regmap_update_bits_base+0x40/0xa0 lr : dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8 ... Call trace: regmap_update_bits_base+0x40/0xa0 dwc3_meson_g12a_usb2_init_phy+0x4c/0xf8 dwc3_meson_g12a_usb2_init+0x7c/0xc8 dwc3_meson_g12a_usb_init+0x28/0x48 dwc3_meson_g12a_probe+0x298/0x540 platform_probe+0x70/0xe0 really_probe+0xf0/0x4d8 driver_probe_device+0xfc/0x168 ...

UnknownCVSS not scoredNot KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysislow

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel bug in a USB controller driver for Amlogic Meson G12A-based systems. On boards where only the second USB2 PHY is used, such as the cited Odroid-HC4 example, the kernel can hit a NULL pointer dereference during USB initialization and crash.

Executive priority

Treat as targeted operational reliability work, not an emergency, unless affected embedded devices are business-critical or remotely managed. Patch through normal kernel maintenance windows after confirming exposure.

Technical view

The dwc3-meson-g12a USB glue driver failed to initialize the PHY1 regmap entry when PHY0 was disabled. Later USB2 initialization called regmap_update_bits_base through a NULL pointer, producing a kernel crash during probe. The source bundle identifies stable kernel fixes but provides no CVSS, CWE, or exploitation detail.

Likely exposure

Exposure appears limited to Linux systems using the affected dwc3-meson-g12a driver and a hardware/device-tree configuration where PHY0 is disabled and PHY1 is active. General servers, desktops, and unrelated embedded platforms are unlikely to be affected based on the provided evidence.

Exploitation context

The bundle does not indicate active exploitation, public exploit code, or KEV listing. The described failure is a kernel NULL pointer dereference during device initialization, suggesting an availability risk on specific hardware rather than a broadly reachable remote attack path.

Researcher notes

Evidence is narrow and kernel-driver-specific. The source bundle names Odroid-HC4 as an example and provides call trace evidence, but no CVSS vector, CWE, exploitability assessment, or distribution-specific fixed versions. Validate against actual board configuration and downstream kernel patches.

Mitigation direction

  • Check vendor kernel packages for the referenced stable fixes.
  • Prioritize affected Meson G12A boards using USB2 PHY1-only configurations.
  • Update to a kernel build containing the stable patch.
  • Avoid changing device-tree USB PHY configuration without regression testing.
  • Track distro advisories for exact fixed package versions.

Validation and detection

  • Inventory devices using Amlogic Meson G12A USB controller support.
  • Check running kernel versions against vendor fixed builds.
  • Review boot logs for dwc3-meson-g12a NULL dereference traces.
  • Confirm whether PHY0 is disabled and PHY1 is used.
  • Regression-test USB initialization after kernel update.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cve · low confidence lookup

CVE-2021-47273 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

0CVSS vectors
3Timeline events
2ADP providers
4Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: partial

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc
CVECVE Program Container

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux013af227f58a97ffc61b99301f8f4448dc7e7f55, 013af227f58a97ffc61b99301f8f4448dc7e7f55, 013af227f58a97ffc61b99301f8f4448dc7e7f55unaffected
LinuxLinux5.8, 0, 5.10.44, 5.12.11, 5.13affected
Weakness

CWE details

No CWE listed

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.