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.
Fix
Microsoft's update · Moderate
- Release Notes — azl3 kernel 6.6.157.1-1 on Azure Linux 3.0 · build 6.6.159.1-1
From the 2026-Oct release note of Microsoft's Security Update Guide, revised 2026-10-28.
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 5
- StatusReceived → PublishedNVD modified 2026-10-21 12:56
- References+1 references (now 5)NVD modified 2026-10-21 13:21
- StatusPublished → ReceivedNVD modified 2026-10-21 13:21
- StatusReceived → PublishedNVD modified 2026-10-19 09:25
- First seenunscoredNVD modified 2026-10-19 10:19
Affected (CPE criteria) 0
NVD has not attached CPE configurations yet.
References 5
- https://git.kernel.org/stable/c/1ff77cbefe5a653ea12874c213ea4bd0d72c1067
- https://git.kernel.org/stable/c/6cd82563bb270e03fe2f91324660ea14e3ce5d1a
- https://git.kernel.org/stable/c/96918ca25ff467c25675478fc79393df4ae9d74c
- https://git.kernel.org/stable/c/ba927133b301894e7d24099afbb701887c8cd2f1
- https://git.kernel.org/stable/c/f51cadb02b439850ab411df0a2cf4288a66d42e2