CVE-2026-89739: usb: dwc3: gadget: Fix use-after-free in dwc3_gadget_free_endpoints due to race condition

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-11 · updated 2026-10-21

Description

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: Fix use-after-free in dwc3_gadget_free_endpoints due to race condition In dwc3_gadget_init_endpoint, &dep->nostream_work is bound with dwc3_nostream_work, and dwc3_gadget_endpoint_stream_event can queue this delayed work on system_percpu_wq when a DEPEVT_STREAM_NOSTREAM event is received. If we remove the gadget, dwc3_gadget_free_endpoints makes cleanup and the memory allocated for dep with kzalloc() is released by kfree(dep), while the delayed work mentioned above may still be pending or running. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | dwc3_thread_interrupt | dwc3_endpoint_interrupt | dwc3_gadget_endpoint_stream_event | queue_delayed_work(system_percpu_wq, | &dep->nostream_work) dwc3_gadget_free_endpoints | dwc3_free_trb_pool(dep) | list_del(&dep->endpoint.ep_list) | dwc3_debugfs_remove_endpoint_dir(dep) | kfree(dep) | // dep is freed | | dwc3_nostream_work | // use dep (use-after-free) Fix it by canceling the delayed work before kfree(dep) in dwc3_gadget_free_endpoints.

Affected products

Linux kernel: from 6.6.160 before 6.7; 6.14 — fixed in 6.7, 7.3

How to fix

Upgrade to a fixed version: Linux kernel 6.7, 7.3. Check the vendor advisory for mitigations.

References

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