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From:   wangyingjie55@126.com
To:     dan.j.williams@intel.com, vishal.l.verma@intel.com,
        dave.jiang@intel.com, ira.weiny@intel.com
Cc:     wangyingjie55@126.com, linux-nvdimm@lists.01.org,
        linux-kernel@vger.kernel.org
Subject: [PATCH v1] libnvdimm, dax: Fix a missing check in nd_dax_probe()
Date:   Wed, 17 Mar 2021 02:32:37 -0700
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From: Yingjie Wang <wangyingjie55@126.com>

In nd_dax_probe()， 'nd_dax' is allocated by nd_dax_alloc().
nd_dax_alloc() may fail and return NULL, so we should better check
it's return value to avoid a NULL pointer dereference
a bit later in the code.

Fixes: c5ed9268643c ("libnvdimm, dax: autodetect support")
Signed-off-by: Yingjie Wang <wangyingjie55@126.com>
---
 drivers/nvdimm/dax_devs.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/nvdimm/dax_devs.c b/drivers/nvdimm/dax_devs.c
index 99965077bac4..b1426ac03f01 100644
--- a/drivers/nvdimm/dax_devs.c
+++ b/drivers/nvdimm/dax_devs.c
@@ -106,6 +106,8 @@ int nd_dax_probe(struct device *dev, struct nd_namespace_common *ndns)
 
 	nvdimm_bus_lock(&ndns->dev);
 	nd_dax = nd_dax_alloc(nd_region);
+	if (!nd_dax)
+		return -ENOMEM;
 	nd_pfn = &nd_dax->nd_pfn;
 	dax_dev = nd_pfn_devinit(nd_pfn, ndns);
 	nvdimm_bus_unlock(&ndns->dev);
-- 
2.7.4