nvme: fix metadata handling in nvme-passthrough

[ 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@lst.de>
Signed-off-by: Puranjay Mohan <pjy@amazon.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Anuj Gupta <anuj20.g@samsung.com>
Signed-off-by: Keith Busch <kbusch@kernel.org>
[ Move the changes from nvme_map_user_request() to nvme_submit_user_cmd()
  to make it work on 4.19 ]
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 6adff541282be115256d64999ad94ac4a2aa2b72..fcf062f3b507d7d6abe049ee7b442b2c655d4119 100644 (file)
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -802,11 +802,16 @@ static int nvme_submit_user_cmd(struct request_queue *q,
        bool write = nvme_is_write(cmd);
        struct nvme_ns *ns = q->queuedata;
        struct gendisk *disk = ns ? ns->disk : NULL;
+       bool supports_metadata = disk && blk_get_integrity(disk);
+       bool has_metadata = meta_buffer && meta_len;
        struct request *req;
        struct bio *bio = NULL;
        void *meta = NULL;
        int ret;
 
+       if (has_metadata && !supports_metadata)
+               return -EINVAL;
+
        req = nvme_alloc_request(q, cmd, 0, NVME_QID_ANY);
        if (IS_ERR(req))
                return PTR_ERR(req);
@@ -821,7 +826,7 @@ static int nvme_submit_user_cmd(struct request_queue *q,
                        goto out;
                bio = req->bio;
                bio->bi_disk = disk;
-               if (disk && meta_buffer && meta_len) {
+               if (has_metadata) {
                        meta = nvme_add_user_metadata(bio, meta_buffer, meta_len,
                                        meta_seed, write);
                        if (IS_ERR(meta)) {