CVE-2026-64583 Details
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.
A use-after-free vulnerability has been identified in the Broadcom BDC USB Device Controller driver within the Linux kernel. This issue arises because the driver improperly manages the lifecycle of its interrupt request (IRQ) handler. The IRQ handler is registered with 'devm_request_irq()', which means it is automatically released by the 'devm' framework only after the 'bdc_remove()' function completes. However, 'bdc_remove()' manually calls several cleanup functions that free critical data structures while the IRQ handler is still active. This creates a window of vulnerability where the IRQ handler can access freed memory, leading to a null pointer dereference or use-after-free condition. Additionally, the driver schedules delayed work that can also interfere with the cleanup process, further exacerbating the issue.
The vulnerability has been fixed by changing the IRQ registration to use 'request_irq()' instead of 'devm_request_irq()'. The 'bdc_remove()' function has been updated to properly release the IRQ before freeing other resources, ensuring that the IRQ handler cannot interfere with the cleanup process.
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CVSS 4.0 Severity and Vector Strings:
No CVSS 4.0 data is available for this CVE.
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
No SSVC data is available for this CVE.
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Weakness Enumeration
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Affected Products
No affected product data is available for this CVE.
Change History
5 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Aug 23, 2026 | CVE Modified | kernel.org |
| Aug 19, 2026 | CVE Modified | kernel.org |
| Aug 17, 2026 | CVE Modified | kernel.org |
| Aug 8, 2026 | CVE Modified | kernel.org |
| Aug 6, 2026 | New CVE Received | kernel.org |