[PATCH 6.1.y] nvme: fix metadata handling in nvme-passthrough

[Puranjay Mohan]

[ Upstream commit 7c2fd76048e95dd267055b5f5e0a48e6e7c81fd9 ]

On an NVMe namespace that does not support metadata, it is possible to
send an IO command with metadata through io-passthru. This allows issues
like [1] to trigger in the completion code path.
nvme_map_user_request() doesn't check if the namespace supports metadata
before sending it forward. It also allows admin commands with metadata to
be processed as it ignores metadata when bdev == NULL and may report
success.

Reject an IO command with metadata when the NVMe namespace doesn't
support it and reject an admin command if it has metadata.

[1] https://lore.kernel.org/all/mb61pcylvnym8.fsf@amazon.com/

Suggested-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Sagi Grimberg <sagi at grimberg.me>
Reviewed-by: Anuj Gupta <anuj20.g at samsung.com>
Signed-off-by: Keith Busch <kbusch at kernel.org>
[ Minor changes to make it work on 6.1 ]
Signed-off-by: Puranjay Mohan <pjy at amazon.com>
---
 drivers/nvme/host/ioctl.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index b3e322e4ade38..a02873792890e 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -3,6 +3,7 @@
  * Copyright (c) 2011-2014, Intel Corporation.
  * Copyright (c) 2017-2021 Christoph Hellwig.
  */
+#include <linux/blk-integrity.h>
 #include <linux/ptrace.h>	/* for force_successful_syscall_return */
 #include <linux/nvme_ioctl.h>
 #include <linux/io_uring.h>
@@ -95,10 +96,15 @@ static int nvme_map_user_request(struct request *req, u64 ubuffer,
 	struct request_queue *q = req->q;
 	struct nvme_ns *ns = q->queuedata;
 	struct block_device *bdev = ns ? ns->disk->part0 : NULL;
+	bool supports_metadata = bdev && blk_get_integrity(bdev->bd_disk);
+	bool has_metadata = meta_buffer && meta_len;
 	struct bio *bio = NULL;
 	void *meta = NULL;
 	int ret;
 
+	if (has_metadata && !supports_metadata)
+		return -EINVAL;
+
 	if (ioucmd && (ioucmd->flags & IORING_URING_CMD_FIXED)) {
 		struct iov_iter iter;
 
@@ -122,7 +128,7 @@ static int nvme_map_user_request(struct request *req, u64 ubuffer,
 	if (bdev)
 		bio_set_dev(bio, bdev);
 
-	if (bdev && meta_buffer && meta_len) {
+	if (has_metadata) {
 		meta = nvme_add_user_metadata(req, meta_buffer, meta_len,
 				meta_seed);
 		if (IS_ERR(meta)) {
-- 
2.40.1