In the Linux kernel, the following vulnerability has been resolved:
USB: gadget: dummy-hcd: Fix wait for outstanding request completions
The dummy-hcd driver emulates synchronize_irq() by waiting until its
private callback_usage counter drops to 0 (with the private lock not
held). This counter is incremented whenever a gadget driver callback
occurs (which requires the private lock to be dropped), but not when a
request completion handler is called.
This is an oversight. Request completion is triggered by timer
interrupts (emulating device IRQs in a real UDC), and the interrupt
handlers are supposed to have completed when the synchronize_irq()
emulation routine returns -- they aren't supposed to be in the middle
of a completion callback. If this happens it can lead to a gadget
driver's unbind routine running before all outstanding request
completions have finished, maybe even allowing the gadget driver's
module to be unloaded while a completion handler is still running.
Fix the oversight by incrementing the callback_usage value across
request completion callbacks.
USB: gadget: dummy-hcd: Fix wait for outstanding request completions
The dummy-hcd driver emulates synchronize_irq() by waiting until its
private callback_usage counter drops to 0 (with the private lock not
held). This counter is incremented whenever a gadget driver callback
occurs (which requires the private lock to be dropped), but not when a
request completion handler is called.
This is an oversight. Request completion is triggered by timer
interrupts (emulating device IRQs in a real UDC), and the interrupt
handlers are supposed to have completed when the synchronize_irq()
emulation routine returns -- they aren't supposed to be in the middle
of a completion callback. If this happens it can lead to a gadget
driver's unbind routine running before all outstanding request
completions have finished, maybe even allowing the gadget driver's
module to be unloaded while a completion handler is still running.
Fix the oversight by incrementing the callback_usage value across
request completion callbacks.
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
Sun, 18 Oct 2026 16:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: USB: gadget: dummy-hcd: Fix wait for outstanding request completions The dummy-hcd driver emulates synchronize_irq() by waiting until its private callback_usage counter drops to 0 (with the private lock not held). This counter is incremented whenever a gadget driver callback occurs (which requires the private lock to be dropped), but not when a request completion handler is called. This is an oversight. Request completion is triggered by timer interrupts (emulating device IRQs in a real UDC), and the interrupt handlers are supposed to have completed when the synchronize_irq() emulation routine returns -- they aren't supposed to be in the middle of a completion callback. If this happens it can lead to a gadget driver's unbind routine running before all outstanding request completions have finished, maybe even allowing the gadget driver's module to be unloaded while a completion handler is still running. Fix the oversight by incrementing the callback_usage value across request completion callbacks. | |
| Title | USB: gadget: dummy-hcd: Fix wait for outstanding request completions | |
| 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: 2026-10-18T15:47:57.358Z
Reserved: 2026-09-25T10:25:14.368Z
Link: CVE-2026-98765
Vulnrichment
No data.
NVD
Status : Received
Published: 2026-10-18T16:17:30.323
Modified: 2026-10-18T16:17:30.323
Link: CVE-2026-98765
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.