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CVE Record

CVE-2021-47583: media: mxl111sf: change mutex_init() location

In the Linux kernel, the following vulnerability has been resolved: media: mxl111sf: change mutex_init() location Syzbot reported, that mxl111sf_ctrl_msg() uses uninitialized mutex. The problem was in wrong mutex_init() location. Previous mutex_init(&state->msg_lock) call was in ->init() function, but dvb_usbv2_init() has this order of calls: dvb_usbv2_init() dvb_usbv2_adapter_init() dvb_usbv2_adapter_frontend_init() props->frontend_attach() props->init() Since mxl111sf_* devices call mxl111sf_ctrl_msg() in ->frontend_attach() internally we need to initialize state->msg_lock before frontend_attach(). To achieve it, ->probe() call added to all mxl111sf_* devices, which will simply initiaize mutex.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysisunknown

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel driver bug in the mxl111sf media device path. The driver could use a mutex before it was initialized during device setup. The public record does not provide a severity score, business impact, or exploit evidence.

Executive priority

Handle through normal kernel maintenance unless the organization uses affected media devices or permits untrusted USB peripherals. Escalate only if vendor guidance later assigns higher severity or exploitation appears.

Technical view

mxl111sf_ctrl_msg() could use state->msg_lock before mutex_init() because dvb_usbv2_init() calls frontend_attach() before props->init(). The fix initializes the mutex earlier by adding probe handling for mxl111sf devices before frontend attachment can call the control-message path.

Likely exposure

Exposure appears limited to Linux systems using affected kernels with mxl111sf media hardware or the relevant driver path enabled. The provided data does not identify distributions, configurations, or remote exposure conditions.

Exploitation context

The source says syzbot reported the issue. CISA KEV status is false, and the bundle provides no evidence of active exploitation, public exploit code, or a practical attack path.

Researcher notes

Evidence is narrow: the record identifies an initialization-order bug and stable fix commits, but no CVSS, CWE, impact class, or exploitability assessment. Avoid assuming privilege escalation or remote attack without additional vendor evidence.

Mitigation direction

  • Update to a Linux kernel containing the referenced stable fixes.
  • Check Linux distribution advisories for packaged kernel updates.
  • If unused, disable or avoid loading the mxl111sf driver where operationally feasible.
  • Prioritize systems that allow untrusted physical USB device attachment.

Validation and detection

  • Inventory Linux kernel versions against vendor security advisories.
  • Check whether the mxl111sf driver is built, loaded, or available.
  • Confirm the relevant stable kernel fix is present in deployed kernels.
  • Review asset classes where USB media devices can be attached.
Prepared
Confidence
medium
Sources
7

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

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ATT&CK lookup starting points

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CVE-2021-47583 mapping review

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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
6Source 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
LinuxLinux8572211842afc53c8450fb470f2b8d02ba7592e0, 8572211842afc53c8450fb470f2b8d02ba7592e0, 8572211842afc53c8450fb470f2b8d02ba7592e0, 8572211842afc53c8450fb470f2b8d02ba7592e0, 8572211842afc53c8450fb470f2b8d02ba7592e0unaffected
LinuxLinux3.7, 0, 4.19.222, 5.4.168, 5.10.88, 5.15.11, 5.16affected
Weakness

CWE details

No CWE listed

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