Security readout for executives and security teams
Plain-English summary
A race in the Linux kernel’s SMC networking code can access memory after it has been freed. A successful attack could potentially compromise confidentiality, integrity, and availability. The supplied record rates it 8.1 High, but does not establish how reliably it can be exploited.
Executive priority
Treat as a high-priority kernel update for SMC-capable or network-facing Linux systems. Accelerate vendor-status checks and patch testing, while avoiding claims of emergency active exploitation because the supplied evidence does not support them.
Technical view
smc_clc_prfx_match() runs from smc_listen_work() without RCU or RTNL protection. Accessing sk_dst_get(sk)->dev can therefore race with destination teardown and cause a use-after-free. The kernel fix uses __sk_dst_get() with dst_dev_rcu(). The caller reportedly does not use the function’s return value.
Likely exposure
Exposure is limited to Linux systems containing the affected SMC code and reaching the relevant listening path. The record identifies version markers including 4.11, 6.17.3, and 6.18, but does not clearly map every vulnerable release or distribution backport. Confirm status with the operating-system vendor.
Exploitation context
The CVSS vector describes network reachability, high attack complexity, no required privileges, and no user interaction. CISA KEV status is false in the supplied bundle, and no cited source establishes active exploitation or a public exploit. Practical prerequisites and exploit reliability remain undocumented here.
Researcher notes
The core issue is unsafe destination-device access outside the expected RCU or RTNL protection. The supplied record names two stable commits, likely reflecting maintained branches, but provides no proof-of-concept, observed attacks, detailed trigger conditions, or complete branch-to-version mapping. Validate fixes by commit or vendor backport metadata.
Mitigation direction
- Install a vendor-supported kernel containing the applicable upstream stable fix.
- Check distribution advisories for backports; kernel version numbers alone may be inconclusive.
- Prioritize systems using or exposing Linux SMC networking.
- Follow vendor guidance if an updated kernel is not yet available.
Validation and detection
- Inventory running kernels and identify systems using Linux SMC networking.
- Compare vendor package changelogs against both cited stable kernel fixes.
- Confirm the corrected kernel is running after maintenance or reboot.
- Review kernel telemetry for relevant crashes or use-after-free reports.
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-2025-40168 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
- 8.1 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:H/PR:N/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:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H2.25.9LinuxVulnerability scoring details
Base CVSS 3.1 score
8.1HighVector: CVSS:3.1/AV:N/AC:H/PR:N/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/d26e80f7fb62d77757b67a1b94e4ac756bc9c658CVE reference, Linux
- https://git.kernel.org/stable/c/235f81045c008169cc4e1955b4a64e118eebe61bCVE 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.