]> git.karo-electronics.de Git - karo-tx-linux.git/commit
usb: dwc2: host: fix use of qtd after free in desc dma mode
authorGregory Herrero <gregory.herrero@intel.com>
Thu, 5 Nov 2015 08:41:40 +0000 (09:41 +0100)
committerFelipe Balbi <balbi@ti.com>
Tue, 15 Dec 2015 15:12:41 +0000 (09:12 -0600)
commit26a19ea699060fded98257e65b0ae5272a5ea1da
treeb5e20b195b70baf3e974bde3dc3e54238ac5eeb5
parentc503b38153852d88774b54ae17f7723f68c6dc33
usb: dwc2: host: fix use of qtd after free in desc dma mode

When completing non isoc xfer, dwc2_complete_non_isoc_xfer_ddma()
is relying on qtd->n_desc to process the corresponding number of
descriptors.

During the processing of these descriptors, qtd could be unlinked
and freed if xfer is done and urb is no more in progress.

In this case, dwc2_complete_non_isoc_xfer_ddma() will read again
qtd->n_desc whereas qtd has been freed. This will lead to unpredictable
results since qtd->n_desc is no more valid value.

To avoid this error, return a result != 0 in dwc2_process_non_isoc_desc(),
so that dwc2_complete_non_isoc_xfer_ddma() stops desc processing.

This has been seen with Slub debug enabled.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Gregory Herrero <gregory.herrero@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
drivers/usb/dwc2/hcd_ddma.c