[PATCH 1/6] nvme-auth: allocate authentication buffer only during transaction

[Hannes Reinecke <hare@suse.de>]

The authentication buffer is only used during the authentication
transaction, so no need to keep it around.

Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 drivers/nvme/host/auth.c | 49 +++++++++++++++++++---------------------
 1 file changed, 23 insertions(+), 26 deletions(-)

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index 3b63aa155beb..b68fb2c764f6 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -667,8 +667,6 @@ static void __nvme_auth_reset(struct nvme_dhchap_queue_context *chap)
 	kfree_sensitive(chap->sess_key);
 	chap->sess_key = NULL;
 	chap->sess_key_len = 0;
-	chap->status = 0;
-	chap->error = 0;
 	chap->s1 = 0;
 	chap->s2 = 0;
 	chap->transaction = 0;
@@ -687,7 +685,6 @@ static void __nvme_auth_free(struct nvme_dhchap_queue_context *chap)
 	kfree_sensitive(chap->host_key);
 	kfree_sensitive(chap->sess_key);
 	kfree_sensitive(chap->host_response);
-	kfree(chap->buf);
 	kfree(chap);
 }
 
@@ -700,6 +697,19 @@ static void __nvme_auth_work(struct work_struct *work)
 	int ret = 0;
 
 	chap->transaction = ctrl->transaction++;
+	chap->status = 0;
+	chap->error = 0;
+
+	/*
+	 * Allocate a large enough buffer for the entire negotiation:
+	 * 4k should be enough to ffdhe8192.
+	 */
+	chap->buf_size = 4096;
+	chap->buf = kzalloc(chap->buf_size, GFP_KERNEL);
+	if (!chap->buf) {
+		chap->error = -ENOMEM;
+		return;
+	}
 
 	/* DH-HMAC-CHAP Step 1: send negotiate */
 	dev_dbg(ctrl->device, "%s: qid %d send negotiate\n",
@@ -707,13 +717,13 @@ static void __nvme_auth_work(struct work_struct *work)
 	ret = nvme_auth_set_dhchap_negotiate_data(ctrl, chap);
 	if (ret < 0) {
 		chap->error = ret;
-		return;
+		goto out_free;
 	}
 	tl = ret;
 	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
 	if (ret) {
 		chap->error = ret;
-		return;
+		goto out_free;
 	}
 
 	/* DH-HMAC-CHAP Step 2: receive challenge */
@@ -727,14 +737,14 @@ static void __nvme_auth_work(struct work_struct *work)
 			 "qid %d failed to receive challenge, %s %d\n",
 			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
 		chap->error = ret;
-		return;
+		goto out_free;
 	}
 	ret = nvme_auth_receive_validate(ctrl, chap->qid, chap->buf, chap->transaction,
 					 NVME_AUTH_DHCHAP_MESSAGE_CHALLENGE);
 	if (ret) {
 		chap->status = ret;
 		chap->error = NVME_SC_AUTH_REQUIRED;
-		return;
+		goto out_free;
 	}
 
 	ret = nvme_auth_process_dhchap_challenge(ctrl, chap);
@@ -790,7 +800,7 @@ static void __nvme_auth_work(struct work_struct *work)
 			 "qid %d failed to receive success1, %s %d\n",
 			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
 		chap->error = ret;
-		return;
+		goto out_free;
 	}
 	ret = nvme_auth_receive_validate(ctrl, chap->qid,
 					 chap->buf, chap->transaction,
@@ -798,7 +808,7 @@ static void __nvme_auth_work(struct work_struct *work)
 	if (ret) {
 		chap->status = ret;
 		chap->error = NVME_SC_AUTH_REQUIRED;
-		return;
+		goto out_free;
 	}
 
 	if (ctrl->ctrl_key) {
@@ -828,10 +838,7 @@ static void __nvme_auth_work(struct work_struct *work)
 		if (ret)
 			chap->error = ret;
 	}
-	if (!ret) {
-		chap->error = 0;
-		return;
-	}
+	goto out_free;
 
 fail2:
 	dev_dbg(ctrl->device, "%s: qid %d send failure2, status %x\n",
@@ -844,6 +851,9 @@ static void __nvme_auth_work(struct work_struct *work)
 	 */
 	if (ret && !chap->error)
 		chap->error = ret;
+out_free:
+	kfree(chap->buf);
+	chap->buf = NULL;
 }
 
 int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
@@ -863,7 +873,6 @@ int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
 	mutex_lock(&ctrl->dhchap_auth_mutex);
 	/* Check if the context is already queued */
 	list_for_each_entry(chap, &ctrl->dhchap_auth_list, entry) {
-		WARN_ON(!chap->buf);
 		if (chap->qid == qid) {
 			dev_dbg(ctrl->device, "qid %d: re-using context\n", qid);
 			mutex_unlock(&ctrl->dhchap_auth_mutex);
@@ -881,18 +890,6 @@ int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
 	chap->qid = (qid == NVME_QID_ANY) ? 0 : qid;
 	chap->ctrl = ctrl;
 
-	/*
-	 * Allocate a large enough buffer for the entire negotiation:
-	 * 4k should be enough to ffdhe8192.
-	 */
-	chap->buf_size = 4096;
-	chap->buf = kzalloc(chap->buf_size, GFP_KERNEL);
-	if (!chap->buf) {
-		mutex_unlock(&ctrl->dhchap_auth_mutex);
-		kfree(chap);
-		return -ENOMEM;
-	}
-
 	INIT_WORK(&chap->auth_work, __nvme_auth_work);
 	list_add(&chap->entry, &ctrl->dhchap_auth_list);
 	mutex_unlock(&ctrl->dhchap_auth_mutex);
-- 
2.35.3