GHSA-VQ5J-5625-RCFR
Vulnerability from github – Published: 2026-08-06 09:30 – Updated: 2026-08-06 09:30In 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.
{
"affected": [],
"aliases": [
"CVE-2026-64583"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-06T08:16:33Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nusb: gadget: udc: bdc: free IRQ and drain func_wake_notify before teardown\n\nThe Broadcom BDC UDC driver registers its IRQ handler with\ndevm_request_irq() in bdc_udc_init(), so the IRQ is released by devm\nonly after bdc_remove() returns. devm releases resources in reverse\nLIFO order, but bdc_remove() runs bdc_udc_exit() and bdc_hw_exit() -\u003e\nbdc_mem_free() manually before returning: bdc_udc_exit() tears down\nindividual endpoint objects via bdc_free_ep(), while bdc_hw_exit() -\u003e\nbdc_mem_free() frees and NULLs the DMA-coherent status-report ring\n(bdc-\u003esrr.sr_bds) and kfree()s bdc-\u003ebdc_ep_array. Both happen while\nthe IRQ handler (bdc_udc_interrupt, requested with IRQF_SHARED)\nremains deliverable in the window up to the post-remove devm\nfree_irq().\n\nOn receipt of a shared interrupt in that window, bdc_udc_interrupt()\ndereferences bdc-\u003esrr.sr_bds[bdc-\u003esrr.dqp_index] (NULL or freed DMA)\nand dispatches sr_handler callbacks that index into bdc_ep_array,\ncausing a NULL-deref or use-after-free.\n\nThe same window affects the delayed_work bdc-\u003efunc_wake_notify, which is\narmed from the IRQ handler via bdc_sr_uspc() -\u003e handle_link_state_change()\n-\u003e schedule_delayed_work() and may self-rearm from its own callback\nbdc_func_wake_timer(). No cancel exists anywhere in the driver, so a\nqueued work item that fires after bdc_remove() returns and the bdc\nstructure is devm-freed dereferences freed memory.\n\nReplace devm_request_irq() with request_irq() and add an explicit\nfree_irq(bdc-\u003eirq, bdc) in bdc_remove(). Clear BDC_GIE before\nfree_irq() to stop the device from asserting interrupts, then\nfree_irq() drains any in-flight handler, then cancel_delayed_work_sync()\ndrains the func_wake_notify delayed work. This ordering ensures the\nIRQ handler and delayed work cannot interfere with the subsequent\nendpoint and DMA teardown in bdc_udc_exit() and bdc_hw_exit(). Wire the\nmatching free_irq() into the bdc_udc_init() error path so the IRQ is\nreleased on probe failure, and route the bdc_init_ep() failure through\nerr0 instead of returning directly.\n\nThis issue was found by an in-house static analysis tool.",
"id": "GHSA-vq5j-5625-rcfr",
"modified": "2026-08-06T09:30:32Z",
"published": "2026-08-06T09:30:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64583"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0583f2fbf8f86ae3a0ce054f96783dd83e65d9bb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1a1d7158420df6b8fa1efc0cdd6ab704801a4fc8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d4964a74717107697999f48bcb4e80a9c0679a27"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dcf3e2f164435b5844706cb8eefef29ebee0eedb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f6fc21ec7ccd83726ba766d73d0b8cc03e726475"
}
],
"schema_version": "1.4.0",
"severity": []
}
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