From: Frode Isaksen frode@meta.com
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: Frode Isaksen frode@meta.com Fixes: ebbb2d59398f ("usb: dwc3: gadget: use evt->cache for processing events") Cc: stable@vger.kernel.org --- v1 -> v2: Added Fixes and Cc tag.
This bug was discovered, tested and fixed (no more crashes seen) on Meta Quest 3 device. Also tested on T.I. AM62x board.
drivers/usb/dwc3/gadget.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 63fef4a1a498..548e112167f3 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4564,7 +4564,7 @@ static irqreturn_t dwc3_check_event_buf(struct dwc3_event_buffer *evt)
count = dwc3_readl(dwc->regs, DWC3_GEVNTCOUNT(0)); count &= DWC3_GEVNTCOUNT_MASK; - if (!count) + if (!count || count > evt->length) return IRQ_NONE;
evt->count = count;