LiveActive security incident?Get immediate response
CVE Record

CVE-2021-47622: scsi: ufs: Fix a deadlock in the error handler

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: Fix a deadlock in the error handler The following deadlock has been observed on a test setup: - All tags allocated - The SCSI error handler calls ufshcd_eh_host_reset_handler() - ufshcd_eh_host_reset_handler() queues work that calls ufshcd_err_handler() - ufshcd_err_handler() locks up as follows: Workqueue: ufs_eh_wq_0 ufshcd_err_handler.cfi_jt Call trace: __switch_to+0x298/0x5d8 __schedule+0x6cc/0xa94 schedule+0x12c/0x298 blk_mq_get_tag+0x210/0x480 __blk_mq_alloc_request+0x1c8/0x284 blk_get_request+0x74/0x134 ufshcd_exec_dev_cmd+0x68/0x640 ufshcd_verify_dev_init+0x68/0x35c ufshcd_probe_hba+0x12c/0x1cb8 ufshcd_host_reset_and_restore+0x88/0x254 ufshcd_reset_and_restore+0xd0/0x354 ufshcd_err_handler+0x408/0xc58 process_one_work+0x24c/0x66c worker_thread+0x3e8/0xa4c kthread+0x150/0x1b4 ret_from_fork+0x10/0x30 Fix this lockup by making ufshcd_exec_dev_cmd() allocate a reserved request.

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

Security readout for executives and security teams

Plain-English summary

This Linux kernel issue can freeze storage recovery on systems using the UFS storage driver. When all request tags are consumed, the error handler can deadlock instead of completing recovery. The available sources describe an availability risk, not data theft or remote code execution.

Executive priority

Treat this as a targeted availability risk. Patch during normal kernel maintenance unless the organization relies on UFS-based Linux devices where storage hangs would disrupt critical operations.

Technical view

The UFS SCSI error path calls ufshcd_eh_host_reset_handler(), which queues ufshcd_err_handler(). During reset and restore, ufshcd_exec_dev_cmd() may allocate a normal block request and block when all tags are allocated. The fix makes device commands use a reserved request to avoid the deadlock.

Likely exposure

Exposure appears limited to Linux systems with the affected UFS driver code and UFS storage hardware or configurations. The version metadata lists Linux 5.6, 5.15.25, 5.16.11, and 5.17, but the source bundle does not provide complete distribution-specific ranges.

Exploitation context

The bundle does not show CISA KEV listing, public exploitation, exploit code, or attacker prerequisites. The described trigger came from a test setup where all tags were allocated and the SCSI error handler entered the UFS reset path.

Researcher notes

Evidence is source-level and kernel-stable focused. No CVSS, CWE, exploitation status, or complete downstream package mapping is provided. Validate exposure against kernel source or vendor backports rather than relying only on upstream version labels.

Mitigation direction

  • Update to a kernel build that includes the referenced stable fixes.
  • Check Linux distribution or device vendor advisories for backported kernel packages.
  • Prioritize systems using UFS storage and affected kernel branches.
  • Monitor for UFS or SCSI error-handler hangs until patched.

Validation and detection

  • Inventory Linux kernel versions and confirm whether UFS support is present.
  • Check vendor kernel changelogs for the referenced UFS reserved-request fix.
  • Review logs for UFS reset, SCSI error-handler, or storage hang symptoms.
  • Confirm patched systems boot and complete storage recovery testing successfully.
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-2021-47622 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

CVECVE Program Container
CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux7252a3603015f1fd04363956f4b72a537c9f9c42, 7252a3603015f1fd04363956f4b72a537c9f9c42, 7252a3603015f1fd04363956f4b72a537c9f9c42, a8d2d45c70c7391386baf7863674f156da56a3d5unaffected
LinuxLinux5.6, 0, 5.15.25, 5.16.11, 5.17affected
Weakness

CWE details

No CWE listed

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