diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index bd59c0e..32a3a5b 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1225,28 +1225,16 @@ static int loop_clr_fd(struct loop_device *lo)
 }
 
 static int
-loop_set_status(struct loop_device *lo, blk_mode_t mode,
-		struct block_device *bdev, const struct loop_info64 *info)
+loop_set_status(struct loop_device *lo, const struct loop_info64 *info)
 {
 	int err;
 	bool partscan = false;
 	bool size_changed = false;
 	unsigned int memflags;
 
-	/*
-	 * If we don't hold exclusive handle for the device, upgrade to it
-	 * here to avoid changing device under exclusive owner.
-	 */
-	if (!(mode & BLK_OPEN_EXCL)) {
-		err = bd_prepare_to_claim(bdev, loop_set_status, NULL);
-		if (err)
-			goto out_reread_partitions;
-	}
-
 	err = mutex_lock_killable(&lo->lo_mutex);
 	if (err)
-		goto out_abort_claiming;
-
+		return err;
 	if (lo->lo_state != Lo_bound) {
 		err = -ENXIO;
 		goto out_unlock;
@@ -1285,10 +1273,6 @@ out_unfreeze:
 	}
 out_unlock:
 	mutex_unlock(&lo->lo_mutex);
-out_abort_claiming:
-	if (!(mode & BLK_OPEN_EXCL))
-		bd_abort_claiming(bdev, loop_set_status);
-out_reread_partitions:
 	if (partscan)
 		loop_reread_partitions(lo);
 
@@ -1368,9 +1352,7 @@ loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info)
 }
 
 static int
-loop_set_status_old(struct loop_device *lo, blk_mode_t mode,
-		    struct block_device *bdev,
-		    const struct loop_info __user *arg)
+loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg)
 {
 	struct loop_info info;
 	struct loop_info64 info64;
@@ -1378,19 +1360,17 @@ loop_set_status_old(struct loop_device *lo, blk_mode_t mode,
 	if (copy_from_user(&info, arg, sizeof (struct loop_info)))
 		return -EFAULT;
 	loop_info64_from_old(&info, &info64);
-	return loop_set_status(lo, mode, bdev, &info64);
+	return loop_set_status(lo, &info64);
 }
 
 static int
-loop_set_status64(struct loop_device *lo, blk_mode_t mode,
-		  struct block_device *bdev,
-		  const struct loop_info64 __user *arg)
+loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg)
 {
 	struct loop_info64 info64;
 
 	if (copy_from_user(&info64, arg, sizeof (struct loop_info64)))
 		return -EFAULT;
-	return loop_set_status(lo, mode, bdev, &info64);
+	return loop_set_status(lo, &info64);
 }
 
 static int
@@ -1569,14 +1549,14 @@ static int lo_ioctl(struct block_device *bdev, blk_mode_t mode,
 	case LOOP_SET_STATUS:
 		err = -EPERM;
 		if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN))
-			err = loop_set_status_old(lo, mode, bdev, argp);
+			err = loop_set_status_old(lo, argp);
 		break;
 	case LOOP_GET_STATUS:
 		return loop_get_status_old(lo, argp);
 	case LOOP_SET_STATUS64:
 		err = -EPERM;
 		if ((mode & BLK_OPEN_WRITE) || capable(CAP_SYS_ADMIN))
-			err = loop_set_status64(lo, mode, bdev, argp);
+			err = loop_set_status64(lo, argp);
 		break;
 	case LOOP_GET_STATUS64:
 		return loop_get_status64(lo, argp);
@@ -1670,9 +1650,8 @@ loop_info64_to_compat(const struct loop_info64 *info64,
 }
 
 static int
-loop_set_status_compat(struct loop_device *lo, blk_mode_t mode,
-		    struct block_device *bdev,
-		    const struct compat_loop_info __user *arg)
+loop_set_status_compat(struct loop_device *lo,
+		       const struct compat_loop_info __user *arg)
 {
 	struct loop_info64 info64;
 	int ret;
@@ -1680,7 +1659,7 @@ loop_set_status_compat(struct loop_device *lo, blk_mode_t mode,
 	ret = loop_info64_from_compat(arg, &info64);
 	if (ret < 0)
 		return ret;
-	return loop_set_status(lo, mode, bdev, &info64);
+	return loop_set_status(lo, &info64);
 }
 
 static int
@@ -1706,7 +1685,7 @@ static int lo_compat_ioctl(struct block_device *bdev, blk_mode_t mode,
 
 	switch(cmd) {
 	case LOOP_SET_STATUS:
-		err = loop_set_status_compat(lo, mode, bdev,
+		err = loop_set_status_compat(lo,
 			     (const struct compat_loop_info __user *)arg);
 		break;
 	case LOOP_GET_STATUS:
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index c2bee32..d86f256 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -816,6 +816,32 @@ static void nvme_unmap_data(struct request *req)
 		nvme_free_descriptors(req);
 }
 
+static bool nvme_pci_prp_save_mapping(struct request *req,
+				      struct device *dma_dev,
+				      struct blk_dma_iter *iter)
+{
+	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+
+	if (dma_use_iova(&iod->dma_state) || !dma_need_unmap(dma_dev))
+		return true;
+
+	if (!iod->nr_dma_vecs) {
+		struct nvme_queue *nvmeq = req->mq_hctx->driver_data;
+
+		iod->dma_vecs = mempool_alloc(nvmeq->dev->dmavec_mempool,
+				GFP_ATOMIC);
+		if (!iod->dma_vecs) {
+			iter->status = BLK_STS_RESOURCE;
+			return false;
+		}
+	}
+
+	iod->dma_vecs[iod->nr_dma_vecs].addr = iter->addr;
+	iod->dma_vecs[iod->nr_dma_vecs].len = iter->len;
+	iod->nr_dma_vecs++;
+	return true;
+}
+
 static bool nvme_pci_prp_iter_next(struct request *req, struct device *dma_dev,
 		struct blk_dma_iter *iter)
 {
@@ -825,12 +851,7 @@ static bool nvme_pci_prp_iter_next(struct request *req, struct device *dma_dev,
 		return true;
 	if (!blk_rq_dma_map_iter_next(req, dma_dev, &iod->dma_state, iter))
 		return false;
-	if (!dma_use_iova(&iod->dma_state) && dma_need_unmap(dma_dev)) {
-		iod->dma_vecs[iod->nr_dma_vecs].addr = iter->addr;
-		iod->dma_vecs[iod->nr_dma_vecs].len = iter->len;
-		iod->nr_dma_vecs++;
-	}
-	return true;
+	return nvme_pci_prp_save_mapping(req, dma_dev, iter);
 }
 
 static blk_status_t nvme_pci_setup_data_prp(struct request *req,
@@ -843,15 +864,8 @@ static blk_status_t nvme_pci_setup_data_prp(struct request *req,
 	unsigned int prp_len, i;
 	__le64 *prp_list;
 
-	if (!dma_use_iova(&iod->dma_state) && dma_need_unmap(nvmeq->dev->dev)) {
-		iod->dma_vecs = mempool_alloc(nvmeq->dev->dmavec_mempool,
-				GFP_ATOMIC);
-		if (!iod->dma_vecs)
-			return BLK_STS_RESOURCE;
-		iod->dma_vecs[0].addr = iter->addr;
-		iod->dma_vecs[0].len = iter->len;
-		iod->nr_dma_vecs = 1;
-	}
+	if (!nvme_pci_prp_save_mapping(req, nvmeq->dev->dev, iter))
+		return iter->status;
 
 	/*
 	 * PRP1 always points to the start of the DMA transfers.
@@ -1219,6 +1233,7 @@ static blk_status_t nvme_prep_rq(struct request *req)
 	iod->nr_descriptors = 0;
 	iod->total_len = 0;
 	iod->meta_total_len = 0;
+	iod->nr_dma_vecs = 0;
 
 	ret = nvme_setup_cmd(req->q->queuedata, req);
 	if (ret)
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index 549a478..bda816d 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -349,11 +349,14 @@ static void nvmet_tcp_free_cmd_buffers(struct nvmet_tcp_cmd *cmd)
 	cmd->req.sg = NULL;
 }
 
+static void nvmet_tcp_fatal_error(struct nvmet_tcp_queue *queue);
+
 static void nvmet_tcp_build_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 {
 	struct bio_vec *iov = cmd->iov;
 	struct scatterlist *sg;
 	u32 length, offset, sg_offset;
+	unsigned int sg_remaining;
 	int nr_pages;
 
 	length = cmd->pdu_len;
@@ -361,9 +364,22 @@ static void nvmet_tcp_build_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 	offset = cmd->rbytes_done;
 	cmd->sg_idx = offset / PAGE_SIZE;
 	sg_offset = offset % PAGE_SIZE;
+	if (!cmd->req.sg_cnt || cmd->sg_idx >= cmd->req.sg_cnt) {
+		nvmet_tcp_fatal_error(cmd->queue);
+		return;
+	}
 	sg = &cmd->req.sg[cmd->sg_idx];
+	sg_remaining = cmd->req.sg_cnt - cmd->sg_idx;
 
 	while (length) {
+		if (!sg_remaining) {
+			nvmet_tcp_fatal_error(cmd->queue);
+			return;
+		}
+		if (!sg->length || sg->length <= sg_offset) {
+			nvmet_tcp_fatal_error(cmd->queue);
+			return;
+		}
 		u32 iov_len = min_t(u32, length, sg->length - sg_offset);
 
 		bvec_set_page(iov, sg_page(sg), iov_len,
@@ -371,6 +387,7 @@ static void nvmet_tcp_build_pdu_iovec(struct nvmet_tcp_cmd *cmd)
 
 		length -= iov_len;
 		sg = sg_next(sg);
+		sg_remaining--;
 		iov++;
 		sg_offset = 0;
 	}