firmware: arm_scmi: Drop handle on protocol bind failures
Summary
| CVE | CVE-2026-93084 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-17 17:18:02 UTC |
| Updated | 2026-09-17 17:18:02 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: firmware: arm_scmi: Drop handle on protocol bind failures The SCMI bus notifier acquires an SCMI handle when the driver core emits BUS_NOTIFY_BIND_DRIVER, before invoking the protocol driver probe callback. The protocol probe path only checks whether sdev->handle is set. If device_link_add() fails after the handle has been acquired, the protocol device can still bind with a valid handle but without the dependency link to the SCMI parent. A concurrent parent unbind can then miss the child and tear down the SCMI instance while the child still holds a handle into it. If the protocol driver probe later fails, for example with -EPROBE_DEFER, the driver core emits BUS_NOTIFY_DRIVER_NOT_BOUND rather than BUS_NOTIFY_UNBOUND_DRIVER. The SCMI notifier only released the handle on BUS_NOTIFY_UNBOUND_DRIVER, so each failed protocol-device bind leaked the SCMI instance users refcount and left sdev->handle set after the failed probe. Make the link helper report failure and drop the acquired handle if the link cannot be created. Also handle BUS_NOTIFY_DRIVER_NOT_BOUND in the same cleanup path used for unbind so failed probes balance the earlier BUS_NOTIFY_BIND_DRIVER acquisition. |
Risk And Classification
EPSS: 0.001680000 probability, percentile 0.065040000 (date 2026-09-18)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 971fc0665f1361f23251e4d85fac4aed1b683505 0f860db24ee95e5da4866303a35e55098b9641b3 git | Not specified |
| CNA | Linux | Linux | affected 971fc0665f1361f23251e4d85fac4aed1b683505 df273eced7cec550465fd1bb82a5d2c3c7d3c437 git | Not specified |
| CNA | Linux | Linux | affected 971fc0665f1361f23251e4d85fac4aed1b683505 a54dc23e8bd2246c28eafffa60b4634f0d1a11cc git | Not specified |
| CNA | Linux | Linux | affected 971fc0665f1361f23251e4d85fac4aed1b683505 77d2985d1e80e67f32026fc03e975c4c83cc543d git | Not specified |
| CNA | Linux | Linux | affected 971fc0665f1361f23251e4d85fac4aed1b683505 e3a5c30d233ca5d3e799a80da806554c703bda13 git | Not specified |
| CNA | Linux | Linux | affected 6.3 | Not specified |
| CNA | Linux | Linux | unaffected 6.3 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.157 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.110 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.52 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.6 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/df273eced7cec550465fd1bb82a5d2c3c7d3c437 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a54dc23e8bd2246c28eafffa60b4634f0d1a11cc | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/77d2985d1e80e67f32026fc03e975c4c83cc543d | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/e3a5c30d233ca5d3e799a80da806554c703bda13 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/0f860db24ee95e5da4866303a35e55098b9641b3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.