| Message ID | 1564044861-1445-1-git-send-email-mathias.nyman@linux.intel.com (mailing list archive) |
|---|---|
| State | Mainlined |
| Commit | d39b5bad8658d6d94cb2d98a44a7e159db4f5030 |
| Headers | show |
| Series | xhci: Fix crash if scatter gather is used with Immediate Data Transfer (IDT). | expand |
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 7a26496..f5c4144 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -2175,7 +2175,8 @@ static inline bool xhci_urb_suitable_for_idt(struct urb *urb) if (!usb_endpoint_xfer_isoc(&urb->ep->desc) && usb_urb_dir_out(urb) && usb_endpoint_maxp(&urb->ep->desc) >= TRB_IDT_MAX_SIZE && urb->transfer_buffer_length <= TRB_IDT_MAX_SIZE && - !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) + !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) && + !urb->num_sgs) return true; return false;
A second regression was found in the immediate data transfer (IDT) support which was added to 5.2 kernel IDT is used to transfer small amounts of data (up to 8 bytes) in the field normally used for data dma address, thus avoiding dma mapping. If the data was not already dma mapped, then IDT support assumed data was in urb->transfer_buffer, and did not take into accound that even small amounts of data (8 bytes) can be in a scatterlist instead. This caused a NULL pointer dereference when sg_dma_len() was used with non-dma mapped data. Solve this by not using IDT if scatter gather buffer list is used. Fixes: 33e39350ebd2 ("usb: xhci: add Immediate Data Transfer support") Cc: <stable@vger.kernel.org> # v5.2 Reported-by: Maik Stohn <maik.stohn@seal-one.com> Tested-by: Maik Stohn <maik.stohn@seal-one.com> CC: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com> --- drivers/usb/host/xhci.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)