Merge tag 'nvme-6.19-2026-02-05' of git://git.infradead.org/nvme into block-6.19

Pull NVMe fixes from Keith:

"- Fix NULL pointer access setting up dma mappings (Keith)
 - Fix invalid memory access from malformed TCP PDU (YunJe)"

* tag 'nvme-6.19-2026-02-05' of git://git.infradead.org/nvme:
  nvmet-tcp: add bounds checks in nvmet_tcp_build_pdu_iovec
  nvme-pci: handle changing device dma map requirements

Author: axboe

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)

drivers/nvme/target/tcp.c

@@ -349,28 +349,45 @@ 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;
 	nr_pages = DIV_ROUND_UP(length, PAGE_SIZE);
 	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,
 				sg->offset + sg_offset);
 
 		length -= iov_len;
 		sg = sg_next(sg);
+		sg_remaining--;
 		iov++;
 		sg_offset = 0;
 	}