sg_io(): use import_iovec()

... and don't skip access_ok() validation.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 5 insertions, 7 deletions

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index e1f71c396193..55b6f15dac90 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -335,16 +335,14 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
                 struct iov_iter i;
                 struct iovec *iov = NULL;
 
-                ret = rw_copy_check_uvector(-1, hdr->dxferp, hdr->iovec_count,
-                                            0, NULL, &iov);
-                if (ret < 0) {
-                        kfree(iov);
+                ret = import_iovec(rq_data_dir(rq),
+                                   hdr->dxferp, hdr->iovec_count,
+                                   0, &iov, &i);
+                if (ret < 0)
                         goto out_free_cdb;
-                }
 
                 /* SG_IO howto says that the shorter of the two wins */
-                iov_iter_init(&i, rq_data_dir(rq), iov, hdr->iovec_count,
-                              min_t(unsigned, ret, hdr->dxfer_len));
+                iov_iter_truncate(&i, hdr->dxfer_len);
 
                 ret = blk_rq_map_user_iov(q, rq, NULL, &i, GFP_KERNEL);
                 kfree(iov);