1 files changed, 42 insertions, 18 deletions

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 14695c6221c8..9b8eaeca6a79 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -82,9 +82,18 @@ static int sg_set_timeout(struct request_queue *q, int __user *p)
 	return err;
 }
 
+static int max_sectors_bytes(struct request_queue *q)
+{
+	unsigned int max_sectors = queue_max_sectors(q);
+
+	max_sectors = min_t(unsigned int, max_sectors, INT_MAX >> 9);
+
+	return max_sectors << 9;
+}
+
 static int sg_get_reserved_size(struct request_queue *q, int __user *p)
 {
-	unsigned val = min(q->sg_reserved_size, queue_max_sectors(q) << 9);
+	int val = min_t(int, q->sg_reserved_size, max_sectors_bytes(q));
 
 	return put_user(val, p);
 }
@@ -98,10 +107,8 @@ static int sg_set_reserved_size(struct request_queue *q, int __user *p)
 
 	if (size < 0)
 		return -EINVAL;
-	if (size > (queue_max_sectors(q) << 9))
-		size = queue_max_sectors(q) << 9;
 
-	q->sg_reserved_size = size;
+	q->sg_reserved_size = min(size, max_sectors_bytes(q));
 	return 0;
 }
 
@@ -272,7 +279,6 @@ static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
 	r = blk_rq_unmap_user(bio);
 	if (!ret)
 		ret = r;
-	blk_put_request(rq);
 
 	return ret;
 }
@@ -283,14 +289,13 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 	unsigned long start_time;
 	ssize_t ret = 0;
 	int writing = 0;
+	int at_head = 0;
 	struct request *rq;
 	char sense[SCSI_SENSE_BUFFERSIZE];
 	struct bio *bio;
 
 	if (hdr->interface_id != 'S')
 		return -EINVAL;
-	if (hdr->cmd_len > BLK_MAX_CDB)
-		return -EINVAL;
 
 	if (hdr->dxfer_len > (queue_max_hw_sectors(q) << 9))
 		return -EIO;
@@ -306,17 +311,26 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 		case SG_DXFER_FROM_DEV:
 			break;
 		}
+	if (hdr->flags & SG_FLAG_Q_AT_HEAD)
+		at_head = 1;
 
+	ret = -ENOMEM;
 	rq = blk_get_request(q, writing ? WRITE : READ, GFP_KERNEL);
 	if (!rq)
-		return -ENOMEM;
+		goto out;
 	blk_rq_set_block_pc(rq);
 
-	if (blk_fill_sghdr_rq(q, rq, hdr, mode)) {
-		blk_put_request(rq);
-		return -EFAULT;
+	if (hdr->cmd_len > BLK_MAX_CDB) {
+		rq->cmd = kzalloc(hdr->cmd_len, GFP_KERNEL);
+		if (!rq->cmd)
+			goto out_put_request;
 	}
 
+	ret = -EFAULT;
+	if (blk_fill_sghdr_rq(q, rq, hdr, mode))
+		goto out_free_cdb;
+
+	ret = 0;
 	if (hdr->iovec_count) {
 		size_t iov_data_len;
 		struct iovec *iov = NULL;
@@ -325,7 +339,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 					    0, NULL, &iov);
 		if (ret < 0) {
 			kfree(iov);
-			goto out;
+			goto out_free_cdb;
 		}
 
 		iov_data_len = ret;
@@ -348,7 +362,7 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 				      GFP_KERNEL);
 
 	if (ret)
-		goto out;
+		goto out_free_cdb;
 
 	bio = rq->bio;
 	memset(sense, 0, sizeof(sense));
@@ -362,13 +376,18 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
 	 * (if he doesn't check that is his problem).
 	 * N.B. a non-zero SCSI status is _not_ necessarily an error.
 	 */
-	blk_execute_rq(q, bd_disk, rq, 0);
+	blk_execute_rq(q, bd_disk, rq, at_head);
 
 	hdr->duration = jiffies_to_msecs(jiffies - start_time);
 
-	return blk_complete_sghdr_rq(rq, hdr, bio);
-out:
+	ret = blk_complete_sghdr_rq(rq, hdr, bio);
+
+out_free_cdb:
+	if (rq->cmd != rq->__cmd)
+		kfree(rq->cmd);
+out_put_request:
 	blk_put_request(rq);
+out:
 	return ret;
 }
 
@@ -438,6 +457,11 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 	}
 
 	rq = blk_get_request(q, in_len ? WRITE : READ, __GFP_WAIT);
+	if (!rq) {
+		err = -ENOMEM;
+		goto error;
+	}
+	blk_rq_set_block_pc(rq);
 
 	cmdlen = COMMAND_SIZE(opcode);
 
@@ -491,7 +515,6 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 	memset(sense, 0, sizeof(sense));
 	rq->sense = sense;
 	rq->sense_len = 0;
-	blk_rq_set_block_pc(rq);
 
 	blk_execute_rq(q, disk, rq, 0);
 
@@ -511,7 +534,8 @@ out:
 	
 error:
 	kfree(buffer);
-	blk_put_request(rq);
+	if (rq)
+		blk_put_request(rq);
 	return err;
 }
 EXPORT_SYMBOL_GPL(sg_scsi_ioctl);