From c55b18181281b2fffadb9e0e8955d74b8b719349 Mon Sep 17 00:00:00 2001
From: Vishal Verma <vishal.l.verma@intel.com>
Date: Fri, 17 Dec 2021 19:25:11 -0700
Subject: [PATCH 061/217] libcxl: fix potential NULL dereference in
 cxl_memdev_nvdimm_bridge_active()

Static analysis points out that the function above has a check for
'if (!bridge)', implying that bridge maybe NULL, but it is dereferenced
before the check, which could result in a NULL dereference.

Fix this by moving any accesses to the bridge structure after the NULL
check.

Link: https://lore.kernel.org/r/20211218022511.314928-1-vishal.l.verma@intel.com
Cc: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
---
 cxl/lib/libcxl.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/cxl/lib/libcxl.c b/cxl/lib/libcxl.c
index f0664be..3390eb9 100644
--- a/cxl/lib/libcxl.c
+++ b/cxl/lib/libcxl.c
@@ -420,12 +420,15 @@ CXL_EXPORT int cxl_memdev_nvdimm_bridge_active(struct cxl_memdev *memdev)
 {
 	struct cxl_ctx *ctx = cxl_memdev_get_ctx(memdev);
 	struct cxl_nvdimm_bridge *bridge = memdev->bridge;
-	char *path = bridge->dev_buf;
-	int len = bridge->buf_len;
+	char *path;
+	int len;
 
 	if (!bridge)
 		return 0;
 
+	path = bridge->dev_buf;
+	len = bridge->buf_len;
+
 	if (snprintf(path, len, "%s/driver", bridge->dev_path) >= len) {
 		err(ctx, "%s: nvdimm bridge buffer too small!\n",
 				cxl_memdev_get_devname(memdev));
-- 
2.27.0