From 38f8c09d9916e76d2907d68fbe69115aef3a5310 Mon Sep 17 00:00:00 2001
From: Yuval Shaia <yuval.shaia.ml@gmail.com>
Date: Sun, 3 Apr 2022 12:52:34 +0300
Subject: [PATCH] hw/pvrdma: Protect against buggy or malicious guest driver

Guest driver might execute HW commands when shared buffers are not yet
allocated.
This could happen on purpose (malicious guest) or because of some other
guest/host address mapping error.
We need to protect againts such case.

Fixes: CVE-2022-1050

Reported-by: Raven <wxhusst@gmail.com>
Signed-off-by: Yuval Shaia <yuval.shaia.ml@gmail.com>
Message-Id: <20220403095234.2210-1-yuval.shaia.ml@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: liuxiangdong <liuxiangdong5@huawei.com>
---
 hw/rdma/vmw/pvrdma_cmd.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/hw/rdma/vmw/pvrdma_cmd.c b/hw/rdma/vmw/pvrdma_cmd.c
index da7ddfa548..89db963c46 100644
--- a/hw/rdma/vmw/pvrdma_cmd.c
+++ b/hw/rdma/vmw/pvrdma_cmd.c
@@ -796,6 +796,12 @@ int pvrdma_exec_cmd(PVRDMADev *dev)
 
     dsr_info = &dev->dsr_info;
 
+    if (!dsr_info->dsr) {
+            /* Buggy or malicious guest driver */
+            rdma_error_report("Exec command without dsr, req or rsp buffers");
+            goto out;
+    }
+
     if (dsr_info->req->hdr.cmd >= sizeof(cmd_handlers) /
                       sizeof(struct cmd_handler)) {
         rdma_error_report("Unsupported command");
-- 
2.27.0