CVE-2026-64583

Description

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: udc: bdc: free IRQ and drain func_wake_notify before teardown The Broadcom BDC UDC driver registers its IRQ handler with devm_request_irq() in bdc_udc_init(), so the IRQ is released by devm only after bdc_remove() returns. devm releases resources in reverse LIFO order, but bdc_remove() runs bdc_udc_exit() and bdc_hw_exit() -> bdc_mem_free() manually before returning: bdc_udc_exit() tears down individual endpoint objects via bdc_free_ep(), while bdc_hw_exit() -> bdc_mem_free() frees and NULLs the DMA-coherent status-report ring (bdc->srr.sr_bds) and kfree()s bdc->bdc_ep_array. Both happen while the IRQ handler (bdc_udc_interrupt, requested with IRQF_SHARED) remains deliverable in the window up to the post-remove devm free_irq(). On receipt of a shared interrupt in that window, bdc_udc_interrupt() dereferences bdc->srr.sr_bds[bdc->srr.dqp_index] (NULL or freed DMA) and dispatches sr_handler callbacks that index into bdc_ep_array, causing a NULL-deref or use-after-free. The same window affects the delayed_work bdc->func_wake_notify, which is armed from the IRQ handler via bdc_sr_uspc() -> handle_link_state_change() -> schedule_delayed_work() and may self-rearm from its own callback bdc_func_wake_timer(). No cancel exists anywhere in the driver, so a queued work item that fires after bdc_remove() returns and the bdc structure is devm-freed dereferences freed memory. Replace devm_request_irq() with request_irq() and add an explicit free_irq(bdc->irq, bdc) in bdc_remove(). Clear BDC_GIE before free_irq() to stop the device from asserting interrupts, then free_irq() drains any in-flight handler, then cancel_delayed_work_sync() drains the func_wake_notify delayed work. This ordering ensures the IRQ handler and delayed work cannot interfere with the subsequent endpoint and DMA teardown in bdc_udc_exit() and bdc_hw_exit(). Wire the matching free_irq() into the bdc_udc_init() error path so the IRQ is released on probe failure, and route the bdc_init_ep() failure through err0 instead of returning directly. This issue was found by an in-house static analysis tool.

Why is this CVE low priority?

Exploitation requires root privileges or CAP_SYS_MODULE to trigger bdc_remove() by unbinding the platform device via sysfs or removing the kernel module.

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Patch details

Severity score breakdown

CVSS version: CVSS v3.0

References

• MITRE
• NVD
• Launchpad
• Debian

Related Ubuntu Security Notices (USN)

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• Linux kernel vulnerabilities
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• USN-8886-1
• Linux kernel (NVIDIA Tegra) vulnerabilities
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Other references

• https://www.cve.org/CVERecord?id=CVE-2026-64583
• https://git.kernel.org/linus/0583f2fbf8f86ae3a0ce054f96783dd83e65d9bb (7.2-rc5)
• https://git.kernel.org/stable/c/0583f2fbf8f86ae3a0ce054f96783dd83e65d9bb
• https://git.kernel.org/stable/c/1a1d7158420df6b8fa1efc0cdd6ab704801a4fc8
• https://git.kernel.org/stable/c/d4964a74717107697999f48bcb4e80a9c0679a27
• https://git.kernel.org/stable/c/dcf3e2f164435b5844706cb8eefef29ebee0eedb
• https://git.kernel.org/stable/c/f6fc21ec7ccd83726ba766d73d0b8cc03e726475