[PATCH v2] nvme: check if the namespace supports metadata in nvme_map_user_request()

From: Puranjay Mohan
Date: Tue Aug 27 2024 - 09:26:32 EST


On an NVMe namespace that does not support metadata, it is possible to
send an IO command with metadata through io-passthru.
nvme_map_user_request() doesn't check if the namespace supports metadata
before sending it forward.

Reject an IO command with metadata when the NVMe namespace doesn't
support it.

Suggested-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Puranjay Mohan <pjy@xxxxxxxxxx>
---
V1: https://lore.kernel.org/all/20240827121701.48792-1-pjy@xxxxxxxxxx/
Changes in V2:
- Add a flag called 'has_metadata' and use it for the support check and
also for the check before calling bio_integrity_map_user()
---
drivers/nvme/host/ioctl.c | 21 +++++++++++++--------
1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index f1d58e70933f..74d963d425c4 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 +120,13 @@ 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 has_metadata = bdev && meta_buffer && meta_len;
struct bio *bio = NULL;
int ret;

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

@@ -143,15 +148,15 @@ 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;
--
2.40.1