Security readout for executives and security teams
Plain-English summary
This is a Linux kernel bug in the Freescale SATA driver. On affected PPC64 systems, unloading the sata_fsl module can trigger a use-after-free and kernel crash. The available sources describe a local driver lifecycle issue, not a remotely exploitable network flaw.
Executive priority
Treat as a targeted stability risk for affected Linux hardware, not a broad internet-facing emergency. Prioritize patching where Freescale SATA and PPC64 systems are operationally important, especially if module unloads occur during maintenance or automation.
Technical view
sata_fsl_remove freed and unmapped host_priv before devres cleanup later called ata_host_stop and sata_fsl_port_stop. port_stop then read from the already unmapped hcr_base, causing a use-after-free. The kernel fix moves iounmap and kfree into a new host_stop callback after port_stop.
Likely exposure
Exposure appears limited to Linux systems using the sata_fsl Freescale SATA driver, especially PPC64 environments where the module can be unloaded. General Linux servers without this driver or hardware path are unlikely to be exposed based on the provided record.
Exploitation context
No active exploitation is identified in the supplied sources, and KEV is false. The documented trigger is local module removal through rmmod or the equivalent driver detach path. Sources do not provide evidence of remote exploitation, privilege escalation, or weaponized public exploit activity.
Researcher notes
The record lacks CVSS, CWE, and detailed version range semantics. The root cause and fix are clear from the kernel description: resource lifetime ordering between remove, devres cleanup, port_stop, and host_stop. Validate against downstream kernel backports rather than raw upstream version strings alone.
Mitigation direction
- Update to a vendor kernel containing the referenced stable fixes.
- Check Linux distribution advisories for exact fixed package versions.
- Avoid unnecessary sata_fsl module unloading until patched.
- Restrict kernel module management to trusted administrators.
Validation and detection
- Inventory systems for loaded or available sata_fsl driver usage.
- Confirm kernel packages include one of the referenced stable fixes.
- Review crash logs for sata_fsl_port_stop or ioread32 faults during module removal.
- Verify PPC64 or Freescale SATA hardware exposure before prioritizing broadly.
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.
CVE-2021-47549 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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
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/cdcd80292106df5cda325426e96495503e41f947CVE reference, Linux
- https://git.kernel.org/stable/c/91ba94d3f7afca195b224f77a72044fbde1389ceCVE reference, Linux
- https://git.kernel.org/stable/c/325ea49fc43cbc03a5e1e37de8f0ca6357ced4b1CVE reference, Linux
- https://git.kernel.org/stable/c/0769449b0a5eabc3545337217ae690e46673e73aCVE reference, Linux
- https://git.kernel.org/stable/c/77393806c76b6b44f1c44bd957788c8bd9152c45CVE reference, Linux
- https://git.kernel.org/stable/c/4a46b2f5dce02539e88a300800812bd24a45e097CVE reference, Linux
- https://git.kernel.org/stable/c/adf098e2a8a1e1fc075d6a5ba2edd13cf7189082CVE reference, Linux
- https://git.kernel.org/stable/c/6c8ad7e8cf29eb55836e7a0215f967746ab2b504CVE 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.