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CVE Record

CVE-2025-23135: RISC-V: KVM: Teardown riscv specific bits after kvm_exit

In the Linux kernel, the following vulnerability has been resolved: RISC-V: KVM: Teardown riscv specific bits after kvm_exit During a module removal, kvm_exit invokes arch specific disable call which disables AIA. However, we invoke aia_exit before kvm_exit resulting in the following warning. KVM kernel module can't be inserted afterwards due to inconsistent state of IRQ. [25469.031389] percpu IRQ 31 still enabled on CPU0! [25469.031732] WARNING: CPU: 3 PID: 943 at kernel/irq/manage.c:2476 __free_percpu_irq+0xa2/0x150 [25469.031804] Modules linked in: kvm(-) [25469.031848] CPU: 3 UID: 0 PID: 943 Comm: rmmod Not tainted 6.14.0-rc5-06947-g91c763118f47-dirty #2 [25469.031905] Hardware name: riscv-virtio,qemu (DT) [25469.031928] epc : __free_percpu_irq+0xa2/0x150 [25469.031976] ra : __free_percpu_irq+0xa2/0x150 [25469.032197] epc : ffffffff8007db1e ra : ffffffff8007db1e sp : ff2000000088bd50 [25469.032241] gp : ffffffff8131cef8 tp : ff60000080b96400 t0 : ff2000000088baf8 [25469.032285] t1 : fffffffffffffffc t2 : 5249207570637265 s0 : ff2000000088bd90 [25469.032329] s1 : ff60000098b21080 a0 : 037d527a15eb4f00 a1 : 037d527a15eb4f00 [25469.032372] a2 : 0000000000000023 a3 : 0000000000000001 a4 : ffffffff8122dbf8 [25469.032410] a5 : 0000000000000fff a6 : 0000000000000000 a7 : ffffffff8122dc10 [25469.032448] s2 : ff60000080c22eb0 s3 : 0000000200000022 s4 : 000000000000001f [25469.032488] s5 : ff60000080c22e00 s6 : ffffffff80c351c0 s7 : 0000000000000000 [25469.032582] s8 : 0000000000000003 s9 : 000055556b7fb490 s10: 00007ffff0e12fa0 [25469.032621] s11: 00007ffff0e13e9a t3 : ffffffff81354ac7 t4 : ffffffff81354ac7 [25469.032664] t5 : ffffffff81354ac8 t6 : ffffffff81354ac7 [25469.032698] status: 0000000200000100 badaddr: ffffffff8007db1e cause: 0000000000000003 [25469.032738] [<ffffffff8007db1e>] __free_percpu_irq+0xa2/0x150 [25469.032797] [<ffffffff8007dbfc>] free_percpu_irq+0x30/0x5e [25469.032856] [<ffffffff013a57dc>] kvm_riscv_aia_exit+0x40/0x42 [kvm] [25469.033947] [<ffffffff013b4e82>] cleanup_module+0x10/0x32 [kvm] [25469.035300] [<ffffffff8009b150>] __riscv_sys_delete_module+0x18e/0x1fc [25469.035374] [<ffffffff8000c1ca>] syscall_handler+0x3a/0x46 [25469.035456] [<ffffffff809ec9a4>] do_trap_ecall_u+0x72/0x134 [25469.035536] [<ffffffff809f5e18>] handle_exception+0x148/0x156 Invoke aia_exit and other arch specific cleanup functions after kvm_exit so that disable gets a chance to be called first before exit.

UnknownCVSS not scoredNot KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

This is a Linux kernel reliability flaw affecting RISC-V KVM cleanup. When the KVM module is removed, cleanup happens in the wrong order, leaving interrupt state inconsistent and preventing KVM from being inserted again. The provided sources do not show remote exploitation or data compromise.

Executive priority

Treat as a targeted availability risk for RISC-V virtualization platforms, not a broad enterprise emergency. Patch affected RISC-V KVM hosts through normal kernel maintenance, with higher priority where virtualization uptime or module reload workflows matter.

Technical view

CVE-2025-23135 concerns RISC-V KVM module teardown. The AIA exit path ran before kvm_exit, so architecture-specific disable logic did not run before IRQ resources were freed, producing a percpu IRQ warning and leaving KVM reload blocked. The fix reorders RISC-V-specific cleanup after kvm_exit.

Likely exposure

Exposure appears limited to Linux systems running RISC-V with KVM, especially environments that unload and reload the KVM module. Organizations without RISC-V virtualization are unlikely to be exposed based on the supplied sources.

Exploitation context

The bundle reports no KEV listing and provides no evidence of active exploitation. The described impact is operational availability: after module removal, KVM may not be insertable again because IRQ state is inconsistent.

Researcher notes

Evidence is limited to the CVE description and Linux stable references. No CVSS, CWE, CPE detail, exploitability analysis, or active exploitation source is provided. The clearest observable condition is a warning during rmmod followed by failed KVM reinsertion.

Mitigation direction

  • Apply the relevant Linux stable kernel update containing the referenced fix commits.
  • Prioritize RISC-V hosts using KVM or AIA interrupt virtualization.
  • Avoid planned KVM module unload/reload workflows on affected RISC-V hosts until patched.
  • Check distribution or kernel vendor advisories for exact fixed package versions.

Validation and detection

  • Inventory Linux RISC-V hosts and identify whether KVM is enabled or loaded.
  • Check kernel versions against vendor guidance and referenced stable fixes.
  • Review operational logs for percpu IRQ warnings during KVM module removal.
  • Confirm patched hosts can unload and reload KVM cleanly in controlled maintenance testing.
Prepared
Confidence
medium
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

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Vulnerability profileCVE Program record
Severity
Unknown
CVSS
Not scored
Known Exploited
No
Published
Official CVE source material

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.

0CVSS vectors
3Timeline events
0ADP providers
4Source links

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  2. CVE publishedCVE Program

    The CVE record was published.

  3. CVE updatedCVE Program

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Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
LinuxLinux54e43320c2ba0c70258a3aea690da38c6ea3293c, 54e43320c2ba0c70258a3aea690da38c6ea3293c, 54e43320c2ba0c70258a3aea690da38c6ea3293cunaffected
LinuxLinux6.4, 0, 6.13.11, 6.14.2, 6.15affected
Weakness

CWE details

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