usb: gadget: udc: bdc: free IRQ and drain func_wake_notify before teardown

published 2026-08-06 3 mo ago modified 2026-08-23 2 mo ago also EUVD-2026-53770

cvss: 7.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 1%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

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.

Patch / fix

fixed in 1 distros 4 links 8

Linux Linux 5.10.266, 5.15.216, 6.1.183, 6.6.148, 6.12.101, 6.18.42, 7.1.6, 7.2

debian ubuntu suse opensuse

linux Debian 12 6.1.187-1
linux Debian 13 6.12.101-1
linux Debian 14 7.1.6-1
linux-6.12 Debian 12 6.12.101-1~deb12u1

debian advisories DEBIAN-CVE-2026-64583

linux Ubuntu 22.04 LTS 5.15.0-198.208
linux Ubuntu 24.04 LTS 6.8.0-147.147
linux Ubuntu 26.04 LTS 7.0.0-38.38
linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
linux-aws Ubuntu 24.04 LTS 6.8.0-1067.70
linux-aws Ubuntu 26.04 LTS 7.0.0-1014.14
linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
linux-gcp Ubuntu 24.04 LTS 6.8.0-1071.79

ubuntu advisories UBUNTU-CVE-2026-64583

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel-64kb SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
kernel-syms SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
kernel-azure SLE Module for Public Cloud 15 SP7 6.4.0-150700.53.81.1
kernel-source SLE Module for Development Tools 15 SP7, SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
kernel-default SLE Workstation Extension 15 SP7, SLE Module for Legacy 15 SP7, SLE Module for Basesystem 15 SP7 +2 more 6.4.0-150700.53.81.1
kernel-zfcpdump SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1
kernel-obs-build SLE Module for Development Tools 15 SP7 6.4.0-150700.53.81.1
kernel-default-base SLE Module for Basesystem 15 SP7 6.4.0-150700.53.81.1.150700.17.45.1

suse advisories SUSE-SU-2026:4254-1 SUSE-SU-2026:23887-1 SUSE-SU-2026:23902-1 SUSE-SU-2026:23897-1 SUSE-SU-2026:23881-1 SUSE-SU-2026:4120-1

kernel-rt openSUSE Leap 16.0 6.12.0-160000.38.1
dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.38.1
kernel-64kb openSUSE Leap 16.0 6.12.0-160000.38.1
kernel-syms openSUSE Leap 16.0 6.12.0-160000.38.1
kernel-azure openSUSE Leap 16.0 6.12.0-160000.38.1
kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.38.1
kernel-source openSUSE Leap 16.0 6.12.0-160000.38.1
kernel-default openSUSE Leap 16.0 6.12.0-160000.38.1

opensuse advisories openSUSE-SU-2026:21910-1 openSUSE-SU-2026:11476-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-64583 updated 2026-11-07

kernel: usb: gadget: udc: bdc: free IRQ and drain func_wake_notify before teardown

Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.12% chance of exploitation in the next 30 days, higher than 1% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.8	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Linux

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2026-64583
NVD CVE-2026-64583

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary