Security readout for executives and security teams
Plain-English summary
CVE-2022-49753 is a Linux kernel bug in DMA channel reference counting. Under local use, the kernel can miscount DMA clients, fail to free channel resources correctly, and hit a use-after-free warning. It is high severity because the CVSS record rates confidentiality, integrity, and availability impact as high.
Executive priority
Prioritize normal emergency patch governance for shared Linux servers and multi-user environments. There is high potential impact if exploited locally, but the provided sources do not show active exploitation or remote attackability.
Technical view
The dmaengine dma_chan_get() path increments client_count twice for public channels: once in balance_ref_count() and again before return. The bad count can prevent expected resource release, produce incorrect /sys/class/dma/*/in_use values, and trigger kref underflow/use-after-free warnings during repeated async_tx module load and unload.
Likely exposure
Exposure is most relevant to Linux systems running affected kernel versions or downstream vendor kernels containing this dmaengine reference-counting flaw. The source identifies Linux as affected and provides stable kernel fix commits, but does not name specific distributions or appliances.
Exploitation context
The CVSS vector is local, low complexity, low privileges, no user interaction. The bundle does not show CISA KEV listing or any cited evidence of active exploitation. Treat exploitation status as unconfirmed, not active-in-the-wild.
Researcher notes
Focus on affected kernel lineage, downstream backports, and dmaengine public channel reference accounting. The provided reproducer evidence is a warning during repeated async_tx module load and unload, but operational impact beyond the CVSS assessment is not fully evidenced in the bundle.
Mitigation direction
- Apply a vendor kernel update containing the referenced stable dmaengine fix.
- If using custom kernels, incorporate the matching upstream stable commit for your branch.
- Check Linux distribution advisories for packaged kernel availability and reboot requirements.
- Prioritize hosts where untrusted local users can access workloads on affected kernels.
Validation and detection
- Inventory kernel versions across Linux servers and compare with vendor-fixed releases.
- Check whether vendor advisories map your kernel package to CVE-2022-49753.
- For custom kernels, verify the dmaengine fix commit is present in source history.
- Review kernel logs for refcount underflow or use-after-free warnings involving dmaengine or async_tx.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
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.
CWE-416: Exact CWE lookup
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Open ATT&CK lookupCVE-2022-49753 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 7.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
SSVC decision data
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H1.85.9CISA-ADPVulnerability scoring details
Base CVSS 3.1 score
7.8HighVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://git.kernel.org/stable/c/1b409e14b4b7af034e0450f95c165b6c5c87dbc1CVE reference, Linux
- https://git.kernel.org/stable/c/c6221afe573413fd2981e291f7df4a58283e0654CVE reference, Linux
- https://git.kernel.org/stable/c/18dd3b30d4c7e8440c63118c7a7b687372b9567fCVE reference, Linux
- https://git.kernel.org/stable/c/42ecd72f02cd657b00b559621e7ef7d2c4d3e5f1CVE reference, Linux
- https://git.kernel.org/stable/c/71c601965532c38030133535f7cd93c1efa75af1CVE reference, Linux
- https://git.kernel.org/stable/c/142d644fd2cc059ffa042fbfb68e766433ef3afdCVE reference, Linux
- https://git.kernel.org/stable/c/f3dc1b3b4750851a94212dba249703dd0e50bb20CVE reference, Linux
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Use After Free
Use After Free represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.