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.
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.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 17 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | firmware: arm_scmi: Drop handle on protocol bind failures | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-17T16:11:03.659Z
Reserved: 2026-09-17T15:57:05.662Z
Link: CVE-2026-93084
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-09-17T17:18:02.460
Modified: 2026-09-17T17:18:02.460
Link: CVE-2026-93084
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.