ksmbd: fix memory leak in parse_lease_state()

[ Upstream commit eb4447bcce915b43b691123118893fca4f372a8f ]

The previous patch that added bounds check for create lease context
introduced a memory leak. When the bounds check fails, the function
returns NULL without freeing the previously allocated lease_ctx_info
structure.

This patch fixes the issue by adding kfree(lreq) before returning NULL
in both boundary check cases.

Fixes: bab703ed8472 ("ksmbd: add bounds check for create lease context")
Signed-off-by: Wang Zhaolong <wangzhaolong1@huawei.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

fs/smb/server/oplock.c

@@ -1496,7 +1496,7 @@ struct lease_ctx_info *parse_lease_state(void *open_req)
 
 		if (le16_to_cpu(cc->DataOffset) + le32_to_cpu(cc->DataLength) <
 		    sizeof(struct create_lease_v2) - 4)
-			return NULL;
+			goto err_out;
 
 		memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE);
 		lreq->req_state = lc->lcontext.LeaseState;
@@ -1512,7 +1512,7 @@ struct lease_ctx_info *parse_lease_state(void *open_req)
 
 		if (le16_to_cpu(cc->DataOffset) + le32_to_cpu(cc->DataLength) <
 		    sizeof(struct create_lease))
-			return NULL;
+			goto err_out;
 
 		memcpy(lreq->lease_key, lc->lcontext.LeaseKey, SMB2_LEASE_KEY_SIZE);
 		lreq->req_state = lc->lcontext.LeaseState;
@@ -1521,6 +1521,9 @@ struct lease_ctx_info *parse_lease_state(void *open_req)
 		lreq->version = 1;
 	}
 	return lreq;
+err_out:
+	kfree(lreq);
+	return NULL;
 }
 
 /**