virtio_blk: avoid DMA to stack for the sense buffer
commit a14d749fcebe97ddf6af6db3d1f6ece85c9ddcb9 upstream.
Most users of BLOCK_PC requests allocate the sense buffer on the stack,
so to avoid DMA to the stack copy them to a field in the heap allocated
virtblk_req structure. Without that any attempt at SCSI passthrough I/O,
including the SG_IO ioctl from userspace will crash the kernel. Note that
this includes running tools like hdparm even when the host does not have
SCSI passthrough enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 file changed