Security readout for executives and security teams
Plain-English summary
A Linux kernel flaw on LoongArch systems can make the machine freeze when specially structured BPF programs use both function calls and tail calls. Exploitation requires local access and permission to run relevant BPF programs. The reported outcome is a kernel hard lockup, creating serious availability risk for exposed LoongArch hosts.
Executive priority
Treat affected LoongArch hosts as a high-priority availability issue, especially when local users or workloads can load BPF programs. Patch promptly through supported vendor channels. Systems on other architectures are not identified as exposed by these sources, so confirm architecture before escalating broadly.
Technical view
The LoongArch BPF JIT emits N prologue instructions during its first pass but N+1 during its second for programs mixing bpf2bpf calls and tail calls. This off-by-one epilogue offset can omit the final jirl instruction, redirect execution to an unexpected instruction, and lock the kernel. The published fix inserts a nop to keep pass lengths aligned.
Likely exposure
Exposure is limited to Linux running on LoongArch with the affected BPF JIT path and users able to load relevant BPF programs. The bundle lists affected Linux entries spanning 6.1 through 6.15, but its version boundaries are ambiguous. Other architectures are not identified as affected.
Exploitation context
The CVSS vector describes a local, low-complexity attack requiring low privileges and no user interaction. No active exploitation is established: the bundle marks the CVE absent from KEV and provides no cited exploitation report. The demonstrated behavior is a kernel hard lockup triggered by BPF programs using tail calls.
Researcher notes
CWE-193 accurately reflects the instruction-count off-by-one. The two JIT passes disagree only when bpf2bpf and tail calls are combined, corrupting epilogue placement. Although CVSS scores confidentiality, integrity, and availability impacts as high, the supplied technical description substantiates hard lockup; it does not document data theft, code execution, or public weaponization.
Mitigation direction
- Update to a vendor-supported kernel containing the applicable stable-kernel fix.
- Confirm downstream distribution backports because package versions may not match upstream numbering.
- Restrict untrusted users from loading BPF programs where operationally feasible.
- Prioritize LoongArch systems providing shared, multi-user, or workload execution access.
Validation and detection
- Inventory Linux hosts and identify those using LoongArch processors.
- Record kernel package versions and compare them with vendor security guidance.
- Verify whether each downstream kernel includes one of the referenced stable fixes.
- Review who can load BPF programs on affected LoongArch hosts.
- Monitor affected systems for unexplained kernel hangs or watchdog resets.
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-193: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCVE-2025-37893 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
2 official scoresWe 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:H1.85.9LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H1.83.6CISA-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
Base CVSS 3.1 score
5.5MediumVector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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/b3ffad2f02db4aace6799fe0049508b8925eae45CVE reference, Linux
- https://git.kernel.org/stable/c/205a2182c51ffebaef54d643e3745e720cded08bCVE reference, Linux
- https://git.kernel.org/stable/c/c74d95a5679741ef428974ab788f5b0758dc78aeCVE reference, Linux
- https://git.kernel.org/stable/c/48b904de2408af5f936f0e03f48dfcddeab58aa0CVE reference, Linux
- https://git.kernel.org/stable/c/7e2586991e36663c9bc48c828b83eab180ad30a9CVE 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.
Off-by-one Error
Off-by-one Error represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.