Commit 63ccd26c authored by Frode Isaksen's avatar Frode Isaksen Committed by Greg Kroah-Hartman
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usb: dwc3: gadget: check that event count does not exceed event buffer length 



The event count is read from register DWC3_GEVNTCOUNT.
There is a check for the count being zero, but not for exceeding the
event buffer length.
Check that event count does not exceed event buffer length,
avoiding an out-of-bounds access when memcpy'ing the event.
Crash log:
Unable to handle kernel paging request at virtual address ffffffc0129be000
pc : __memcpy+0x114/0x180
lr : dwc3_check_event_buf+0xec/0x348
x3 : 0000000000000030 x2 : 000000000000dfc4
x1 : ffffffc0129be000 x0 : ffffff87aad60080
Call trace:
__memcpy+0x114/0x180
dwc3_interrupt+0x24/0x34

Signed-off-by: default avatarFrode Isaksen <frode@meta.com>
Fixes: 72246da4 ("usb: Introduce DesignWare USB3 DRD Driver")
Cc: stable <stable@kernel.org>
Acked-by: default avatarThinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20250403072907.448524-1-fisaksen@baylibre.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 9ab75eee

drivers/usb/dwc3/gadget.c

+6 −0
Original line number Diff line number Diff line
@@ -4617,6 +4617,12 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt) 
	if (!count)

		return IRQ_NONE;



	if (count > evt->length) {

		dev_err_ratelimited(dwc->dev, "invalid count(%u) > evt->length(%u)\n",

			count, evt->length);

		return IRQ_NONE;

	}



	evt->count = count;

	evt->flags |= DWC3_EVENT_PENDING;