diff options
| -rw-r--r-- | block/scsi_ioctl.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c index 84b7f8709f41..82a0ca2f6729 100644 --- a/block/scsi_ioctl.c +++ b/block/scsi_ioctl.c @@ -290,6 +290,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, if (hdr->iovec_count) { const int size = sizeof(struct sg_iovec) * hdr->iovec_count; + size_t iov_data_len; struct sg_iovec *iov; iov = kmalloc(size, GFP_KERNEL); @@ -304,8 +305,18 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk, goto out; } + /* SG_IO howto says that the shorter of the two wins */ + iov_data_len = iov_length((struct iovec *)iov, + hdr->iovec_count); + if (hdr->dxfer_len < iov_data_len) { + hdr->iovec_count = iov_shorten((struct iovec *)iov, + hdr->iovec_count, + hdr->dxfer_len); + iov_data_len = hdr->dxfer_len; + } + ret = blk_rq_map_user_iov(q, rq, NULL, iov, hdr->iovec_count, - hdr->dxfer_len, GFP_KERNEL); + iov_data_len, GFP_KERNEL); kfree(iov); } else if (hdr->dxfer_len) ret = blk_rq_map_user(q, rq, NULL, hdr->dxferp, hdr->dxfer_len, |