[PATCH AUTOSEL 6.11 067/244] nvme: fix metadata handling in nvme-passthrough

Sasha Levin
2024-09-25T11:39:21Z

From: Puranjay Mohan <pjy@amazon.com>

[ 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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvme/host/ioctl.c | 22 ++++++++++++++--------
1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index f1d58e70933f5..15c93ce07e263 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -4,6 +4,7 @@
* Copyright (c) 2017-2021 Christoph Hellwig.
*/
#include <linux/bio-integrity.h>
+#include <linux/blk-integrity.h>
#include <linux/ptrace.h> /* for force_successful_syscall_return */
#include <linux/nvme_ioctl.h>
#include <linux/io_uring/cmd.h>
@@ -119,9 +120,14 @@ 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;
int ret;

+ if (has_metadata && !supports_metadata)
+ return -EINVAL;
+
if (ioucmd && (ioucmd->flags & IORING_URING_CMD_FIXED)) {
struct iov_iter iter;

@@ -143,15 +149,15 @@ static int nvme_map_user_request(struct request *req, u64 ubuffer,
goto out;

bio = req->bio;
- if (bdev) {
+ if (bdev)
bio_set_dev(bio, bdev);
- if (meta_buffer && meta_len) {
- ret = bio_integrity_map_user(bio, meta_buffer, meta_len,
- meta_seed);
- if (ret)
- goto out_unmap;
- req->cmd_flags |= REQ_INTEGRITY;
- }
+
+ if (has_metadata) {
+ ret = bio_integrity_map_user(bio, meta_buffer, meta_len,
+ meta_seed);
+ if (ret)
+ goto out_unmap;
+ req->cmd_flags |= REQ_INTEGRITY;
}

return ret;
--
2.43.0