[PATCH 5.15.y] nvmet: always initialize cqe.result

[PATCH 5.15.y] nvmet: always initialize cqe.result

[Leon Chen]

From: Daniel Wagner <dwagner@suse.de>

[ Upstream commit cd0c1b8e045a8d2785342b385cb2684d9b48e426 ]

The spec doesn't mandate that the first two double words (aka results)
for the command queue entry need to be set to 0 when they are not
used (not specified). Though, the target implemention returns 0 for TCP
and FC but not for RDMA.

Let's make RDMA behave the same and thus explicitly initializing the
result field. This prevents leaking any data from the stack.

Signed-off-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
[ Ignored the fabrics-cmd-auth.c, it was introduced in commit:db1312dd9548
("nvmet: implement basic In-Band Authentication") ]
Signed-off-by: Leon Chen <leonchen.oss@139.com>
---
 drivers/nvme/target/core.c        | 1 +
 drivers/nvme/target/fabrics-cmd.c | 6 ------
 2 files changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/nvme/target/core.c b/drivers/nvme/target/core.c
index ef2e500bccfd..65bc1efa33d6 100644
--- a/drivers/nvme/target/core.c
+++ b/drivers/nvme/target/core.c
@@ -932,6 +932,7 @@ bool nvmet_req_init(struct nvmet_req *req, struct nvmet_cq *cq,
 	req->metadata_sg_cnt = 0;
 	req->transfer_len = 0;
 	req->metadata_len = 0;
+	req->cqe->result.u64 = 0;
 	req->cqe->status = 0;
 	req->cqe->sq_head = 0;
 	req->ns = NULL;
diff --git a/drivers/nvme/target/fabrics-cmd.c b/drivers/nvme/target/fabrics-cmd.c
index e5ee3d3ce164..a12f80869d6f 100644
--- a/drivers/nvme/target/fabrics-cmd.c
+++ b/drivers/nvme/target/fabrics-cmd.c
@@ -187,9 +187,6 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
 	if (status)
 		goto out;
 
-	/* zero out initial completion result, assign values as needed */
-	req->cqe->result.u32 = 0;
-
 	if (c->recfmt != 0) {
 		pr_warn("invalid connect version (%d).\n",
 			le16_to_cpu(c->recfmt));
@@ -255,9 +252,6 @@ static void nvmet_execute_io_connect(struct nvmet_req *req)
 	if (status)
 		goto out;
 
-	/* zero out initial completion result, assign values as needed */
-	req->cqe->result.u32 = 0;
-
 	if (c->recfmt != 0) {
 		pr_warn("invalid connect version (%d).\n",
 			le16_to_cpu(c->recfmt));
-- 
2.35.3