From 7645f21f409b67eb9aad9feef6283c2e186e3703 Mon Sep 17 00:00:00 2001
From: Klaus Jensen <k.jensen@samsung.com>
Date: Wed, 7 Apr 2021 07:16:14 +0200
Subject: [PATCH] hw/block/nvme: fix out-of-bounds read in nvme_subsys_ctrl

nvme_subsys_ctrl() is used in contexts where the given controller
identifier is from an untrusted source. Like its friends nvme_ns() and
nvme_subsys_ns(), nvme_subsys_ctrl() should just return NULL if an
invalid identifier is given.

Fixes: 645ce1a70cb6 ("hw/block/nvme: support namespace attachment command")
Cc: Minwoo Im <minwoo.im.dev@gmail.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
---
 hw/block/nvme-subsys.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/block/nvme-subsys.h b/hw/block/nvme-subsys.h
index 1cbcad9be2..7d7ef5f7f1 100644
--- a/hw/block/nvme-subsys.h
+++ b/hw/block/nvme-subsys.h
@@ -36,7 +36,7 @@ int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp);
 static inline NvmeCtrl *nvme_subsys_ctrl(NvmeSubsystem *subsys,
         uint32_t cntlid)
 {
-    if (!subsys) {
+    if (!subsys || cntlid >= NVME_SUBSYS_MAX_CTRLS) {
         return NULL;
     }