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CVE Record

CVE-2022-49220: dax: make sure inodes are flushed before destroy cache

In the Linux kernel, the following vulnerability has been resolved: dax: make sure inodes are flushed before destroy cache A bug can be triggered by following command $ modprobe nd_pmem && modprobe -r nd_pmem [ 10.060014] BUG dax_cache (Not tainted): Objects remaining in dax_cache on __kmem_cache_shutdown() [ 10.060938] Slab 0x0000000085b729ac objects=9 used=1 fp=0x000000004f5ae469 flags=0x200000000010200(slab|head|node) [ 10.062433] Call Trace: [ 10.062673] dump_stack_lvl+0x34/0x44 [ 10.062865] slab_err+0x90/0xd0 [ 10.063619] __kmem_cache_shutdown+0x13b/0x2f0 [ 10.063848] kmem_cache_destroy+0x4a/0x110 [ 10.064058] __x64_sys_delete_module+0x265/0x300 This is caused by dax_fs_exit() not flushing inodes before destroy cache. To fix this issue, call rcu_barrier() before destroy cache.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

CVE-2022-49220 is a Linux kernel DAX cleanup bug. When the nd_pmem module is removed, leftover DAX cache objects can trigger a kernel BUG during cache shutdown. The business concern is mainly availability or operational instability on systems using persistent memory/DAX, not confirmed remote compromise.

Executive priority

Treat as a targeted kernel stability issue. Prioritize specialized Linux infrastructure using persistent memory over general servers. No public source provided evidence of active exploitation or remote attack paths, but kernel updates should be scheduled through normal maintenance.

Technical view

The issue is in Linux kernel DAX teardown: dax_fs_exit() destroys dax_cache without first flushing pending inode RCU callbacks. The resolved fix calls rcu_barrier() before destroying the cache. The CVE record lists Linux kernel versions including 4.12 through 5.18-era branches as affected, with multiple stable commit references.

Likely exposure

Systems most likely exposed are Linux hosts using DAX or persistent memory features, especially where the nd_pmem module is present and can be unloaded. Exposure depends on the distribution kernel version and whether the referenced stable fixes are included.

Exploitation context

The public record describes a reproducible kernel BUG when nd_pmem is loaded and then removed. There is no KEV listing and no cited evidence of active exploitation. The described trigger implies local module-management capability, not unauthenticated remote access.

Researcher notes

The CVE data lacks CVSS, CWE, and detailed distribution mapping. The clearest impact is a kernel BUG during DAX cache teardown. Avoid assuming broader privilege escalation or remote exploitability without additional vendor analysis.

Mitigation direction

  • Apply Linux kernel or distribution updates containing the referenced stable fixes.
  • Check vendor advisories for exact affected and fixed package versions.
  • Prioritize hosts using DAX, NVDIMM, or persistent memory features.
  • If no update exists, follow vendor guidance before changing DAX or module behavior.

Validation and detection

  • Inventory Linux systems using DAX, NVDIMM, or nd_pmem-related functionality.
  • Compare running kernel builds against vendor advisories and referenced stable commits.
  • Verify the fix adding rcu_barrier() before dax_cache destruction is present.
  • Review kernel logs for BUG messages referencing dax_cache shutdown.
Prepared
Confidence
medium
Sources
8

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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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
0ADP providers
7Source links

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.

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux7b6be8444e0f0dd675b54d059793423d3c9b4c03, 7b6be8444e0f0dd675b54d059793423d3c9b4c03, 7b6be8444e0f0dd675b54d059793423d3c9b4c03, 7b6be8444e0f0dd675b54d059793423d3c9b4c03, 7b6be8444e0f0dd675b54d059793423d3c9b4c03, 7b6be8444e0f0dd675b54d059793423d3c9b4c03unaffected
LinuxLinux4.12, 0, 5.4.189, 5.10.110, 5.15.33, 5.16.19, 5.17.2, 5.18affected
Weakness

CWE details

No CWE listed

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