CVEvulnerability
CVE-2026-98767
- Status
- Received
- Published
- 2026-10-18
- Last modified
- 2026-10-21
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
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.
References
- https://git.kernel.org/stable/c/1ff77cbefe5a653ea12874c213ea4bd0d72c1067 git.kernel.org
- https://git.kernel.org/stable/c/6cd82563bb270e03fe2f91324660ea14e3ce5d1a git.kernel.org
- https://git.kernel.org/stable/c/96918ca25ff467c25675478fc79393df4ae9d74c git.kernel.org
- https://git.kernel.org/stable/c/ba927133b301894e7d24099afbb701887c8cd2f1 git.kernel.org
- https://git.kernel.org/stable/c/f51cadb02b439850ab411df0a2cf4288a66d42e2 git.kernel.org