In the Linux kernel, the following vulnerability has been resolved: xhci: handle isoc Babble and Buffer Overrun events properly xHCI 4.9 explicitly forbids assuming that the xHC has released its ownership of a multi-TRB TD when it reports an error on one of the early TRBs. Yet the driver makes such assumption and releases the TD, allowing the remaining TRBs to be freed or overwritten by new TDs. The xHC should also report completion of the final TRB due to its IOC flag being set by us, regardless of prior errors. This event cannot be recognized if the TD has already been freed earlier, resulting in "Transfer event TRB DMA ptr not part of current TD" error message. Fix this by reusing the logic for processing isoc Transaction Errors. This also handles hosts which fail to report the final completion. Fix transfer length reporting on Babble errors. They may be caused by device malfunction, no guarantee that the buffer has been filled. A flaw was found in the Linux kernel related to the Extensible Host Controller Interface (xHCI) subsystem, specifically how it handles certain events. The issue arises when the xHCI driver improperly handles isochronous (isoc) Babble and Buffer Overrun events. The vulnerability occurs because the xHCI driver incorrectly assumes that the xHC (host controller) has released its ownership of a multi-TRB (Transfer Request Block) TD (Transfer Descriptor) after reporting an error on an early TRB. This assumption leads to the premature release of the TD, allowing remaining TRBs to be freed or overwritten, which can cause system instability or crashes.
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