diff options
| -rw-r--r-- | drivers/scsi/sg.c | 28 |
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index ffc87851f2e..1e405184ed7 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1656,10 +1656,30 @@ static int sg_start_req(Sg_request *srp, unsigned char *cmd) md->null_mapped = hp->dxferp ? 0 : 1; } - if (iov_count) - res = blk_rq_map_user_iov(q, rq, md, hp->dxferp, iov_count, - hp->dxfer_len, GFP_ATOMIC); - else + if (iov_count) { + int len, size = sizeof(struct sg_iovec) * iov_count; + struct iovec *iov; + + iov = kmalloc(size, GFP_ATOMIC); + if (!iov) + return -ENOMEM; + + if (copy_from_user(iov, hp->dxferp, size)) { + kfree(iov); + return -EFAULT; + } + + len = iov_length(iov, iov_count); + if (hp->dxfer_len < len) { + iov_count = iov_shorten(iov, iov_count, hp->dxfer_len); + len = hp->dxfer_len; + } + + res = blk_rq_map_user_iov(q, rq, md, (struct sg_iovec *)iov, + iov_count, + len, GFP_ATOMIC); + kfree(iov); + } else res = blk_rq_map_user(q, rq, md, hp->dxferp, hp->dxfer_len, GFP_ATOMIC); |