Security readout for executives and security teams
Plain-English summary
A locking error in the Linux smc91x network driver can leave interrupts improperly disabled on real-time kernels, potentially causing serious availability problems. Exposure is narrow: the driver must be present and PREEMPT_RT enabled. The supplied CVSS score is 7.5, but the bundle provides no evidence of exploitation in the wild.
Executive priority
Prioritize promptly where PREEMPT_RT systems use smc91x for critical connectivity; otherwise, schedule normal patching after confirming configuration. The high score reflects potential loss of availability, not confidentiality or integrity compromise. Current evidence does not justify an emergency response across Linux estates generally.
Technical view
On PREEMPT_RT, smc_special_trylock() disabled IRQs while smc_special_unlock() failed to restore the expected IRQ context. This disrupted RCU and bottom-half handling during network transmission, producing a workqueue atomic/lock/RCU leak warning. The upstream correction replaces the custom try-lock operation with spin_trylock_irqsave(). Impact is availability-only according to the supplied CVSS vector.
Likely exposure
Likely limited to Linux systems using the smc91x Ethernet driver with PREEMPT_RT. The bundle identifies affected 5.15, 6.1, 6.6, 6.12, 6.18, and 6.19 lines, but its flattened version data does not clearly establish exact vulnerable ranges. Confirm exposure against the applicable stable-branch commit or distribution advisory.
Exploitation context
CISA KEV status is false, and the supplied sources do not report active exploitation or a public exploit. Although the CVSS vector marks network reachability, successful impact appears dependent on the smc91x driver, PREEMPT_RT, and relevant network activity. Treat claims of broad remote exploitability as unverified.
Researcher notes
The documented failure was reproduced on FVP_RevC with a PREEMPT_RT 6.18 development kernel. The causal account centers on asymmetric IRQ handling and RCU bottom-half state during __dev_queue_xmit(). No CWE, exploit proof, attack trigger details, or confirmed fixed package versions are supplied. Stable commits exist for multiple maintained branches.
Mitigation direction
- Update to a vendor kernel containing the applicable referenced stable-branch fix.
- If immediate updating is impossible, assess whether the smc91x driver can be safely disabled.
- Prioritize affected real-time systems supporting critical networked or operational workloads.
- Consult the Linux distribution vendor for exact fixed package versions.
Validation and detection
- Confirm whether the running kernel uses PREEMPT_RT.
- Determine whether the smc91x driver is built, loaded, and attached to active hardware.
- Map the installed kernel branch to its applicable referenced stable commit.
- Review kernel logs for smc91x-related atomic, lock, RCU, or workqueue warnings.
- After remediation, verify the vendor fix is present and repeat normal network stability testing.
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
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ATT&CK lookup starting points
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CVE-2025-71132 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
- 7.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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:L/PR:N/UI:N/S:U/C:N/I:N/A:H3.93.6LinuxVulnerability scoring details
Base CVSS 3.1 score
7.5HighVector: CVSS:3.1/AV:N/AC:L/PR:N/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/1c4cb705e733250d13243f6a69b8b5a92e39b9f6CVE reference, Linux
- https://git.kernel.org/stable/c/9d222141b00156509d67d80c771fbefa92c43aceCVE reference, Linux
- https://git.kernel.org/stable/c/ef277ae121b3249c99994652210a326b52d527b0CVE reference, Linux
- https://git.kernel.org/stable/c/36561b86cb2501647662cfaf91286dd6973804a6CVE reference, Linux
- https://git.kernel.org/stable/c/b6018d5c1a8f09d5efe4d6961d7ee45fdf3a7ce3CVE reference, Linux
- https://git.kernel.org/stable/c/6402078bd9d1ed46e79465e1faaa42e3458f8a33CVE 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.