From: Jan H. Schönherr <jschoenh@amazon.de>
Date: Sun, 27 Aug 2017 13:56:37 +0000 (+0200)
Subject: nvme: fix uninitialized prp2 value on small transfers
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5228b3280b9bb8fa6aef59f891cca64a028e9b36;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

nvme: fix uninitialized prp2 value on small transfers

The value of iod->first_dma ends up as prp2 in NVMe commands. In case
there is not enough data to cross a page boundary, iod->first_dma is
never initialized and contains random data.

Comply with the NVMe specification and fill in 0 in that case.

Signed-off-by: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---

diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index e6283745ecd2..544805a2421b 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -555,8 +555,10 @@ static blk_status_t nvme_setup_prps(struct nvme_dev *dev, struct request *req)
 	int nprps, i;
 
 	length -= (page_size - offset);
-	if (length <= 0)
+	if (length <= 0) {
+		iod->first_dma = 0;
 		return BLK_STS_OK;
+	}
 
 	dma_len -= (page_size - offset);
 	if (dma_len) {