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| author | Mathias Nyman <mathias.nyman@linux.intel.com> | 2019-07-25 11:54:21 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-25 11:26:42 +0200 |
| commit | d39b5bad8658d6d94cb2d98a44a7e159db4f5030 (patch) | |
| tree | 01c78843d3a55fd30bd7c7cf7f13c3357dacbbf4 | |
| parent | 4849ee6129702dcb05d36f9c7c61b4661fcd751f (diff) | |
| download | linux-d39b5bad8658d6d94cb2d98a44a7e159db4f5030.tar.bz2 | |
xhci: Fix crash if scatter gather is used with Immediate Data Transfer (IDT).
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>
Link: https://lore.kernel.org/r/1564044861-1445-1-git-send-email-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/host/xhci.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 7a264962a1a9..f5c41448d067 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; |