CVE-2026-89739

Published Sep 11, 2026

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.

Is your site exposed to CVE-2026-89739?

Run a free security scan — no signup, results in seconds.

References

Frequently Asked Questions

What is CVE-2026-89739? +
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.
How do I check if I'm vulnerable to CVE-2026-89739? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Don't wait for an exploit

Scan your website for vulnerabilities like CVE-2026-89739 — free, no signup required.