CVE-2026-98767

usb: dwc3: gadget: fix IRQ storm on invalid event buffer count

Published Oct 18, 2026 CVSS 3.1 · 5.1 Medium EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

usb: dwc3: gadget: fix IRQ storm on invalid event buffer count

When dwc3_check_event_buf() reads a GEVNTCOUNT value exceeding the
event buffer length, commit 63ccd26cd1f6 ("usb: dwc3: gadget: check
that event count does not exceed event buffer length") returns IRQ_NONE
without writing back GEVNTCOUNT. Since the DWC3 interrupt is
level-triggered, the uncleared IRQ source keeps the line asserted,
causing a tight IRQ storm that accumulates 99,900 unhandled interrupts
and triggers spurious.c:184 BUG -> kernel panic.

The resulting call stack:
__report_bad_irq+0xac/0xc8
note_interrupt+0x340/0x468
handle_irq_event+0xac/0xc0
handle_fasteoi_irq+0x120/0x228
gic_handle_irq+0x68/0x108
...
kernel BUG at kernel/irq/spurious.c:184

To reproduce, write a bogus value exceeding the event buffer length
directly to the GEVNTCOUNT register:

devmem <DWC3_BASE + 0xc40c> 4 0x1004

Write the bogus count back to GEVNTCOUNT to clear the IRQ source,
consistent with the stale event clearing pattern in
dwc3_event_buffers_setup(), and schedule error recovery to
reinitialize the controller.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4850-1 linux-6.12 security update
Ubuntu USN Ubuntu USN USN-9018-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9018-2 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9022-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9023-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9024-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9025-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9026-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9039-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-9040-1 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9066-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-668
Type Values Removed Values Added
Weaknesses CWE-390
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.1, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Weaknesses CWE-668
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: gadget: fix IRQ storm on invalid event buffer count When dwc3_check_event_buf() reads a GEVNTCOUNT value exceeding the event buffer length, commit 63ccd26cd1f6 ("usb: dwc3: gadget: check that event count does not exceed event buffer length") returns IRQ_NONE without writing back GEVNTCOUNT. Since the DWC3 interrupt is level-triggered, the uncleared IRQ source keeps the line asserted, causing a tight IRQ storm that accumulates 99,900 unhandled interrupts and triggers spurious.c:184 BUG -> kernel panic. The resulting call stack: __report_bad_irq+0xac/0xc8 note_interrupt+0x340/0x468 handle_irq_event+0xac/0xc0 handle_fasteoi_irq+0x120/0x228 gic_handle_irq+0x68/0x108 ... kernel BUG at kernel/irq/spurious.c:184 To reproduce, write a bogus value exceeding the event buffer length directly to the GEVNTCOUNT register: devmem <DWC3_BASE + 0xc40c> 4 0x1004 Write the bogus count back to GEVNTCOUNT to clear the IRQ source, consistent with the stale event clearing pattern in dwc3_event_buffers_setup(), and schedule error recovery to reinitialize the controller.
Title usb: dwc3: gadget: fix IRQ storm on invalid event buffer count
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 30, 2026, 12:39 PM
Reserved
Sep 25, 2026, 10:25 AM
Status
Received
Published
Oct 18, 2026, 4:17 PM
Modified
Oct 30, 2026, 1:21 PM
Severity
Moderate
Public date
Oct 18, 2026, 12:00 AM