RE: [PATCH] hv_netvsc: Fix potential dereference of NULL pointer

-----Original Message-----
From: Yongzhi Liu <redacted>
Sent: Thursday, May 19, 2022 8:10 AM
To: KY Srinivasan <kys@microsoft.com>; Haiyang Zhang
[off-list ref]; Stephen Hemminger
[off-list ref]; wei.liu@kernel.org; Dexuan Cui
[off-list ref]; davem@davemloft.net; kuba@kernel.org;
pabeni@redhat.com; sashal@kernel.org
Cc: linux-hyperv@vger.kernel.org; netdev@vger.kernel.org; linux-
kernel@vger.kernel.org; fuyq@stu.pku.edu.cn; Yongzhi Liu
[off-list ref]
Subject: [PATCH] hv_netvsc: Fix potential dereference of NULL pointer

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The return value of netvsc_devinfo_get()
needs to be checked to avoid use of NULL
pointer in case of an allocation failure.

Fixes: 0efeea5fb ("hv_netvsc: Add the support of hibernation")

Signed-off-by: Yongzhi Liu <redacted>
---
 drivers/net/hyperv/netvsc_drv.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c

b/drivers/net/hyperv/netvsc_drv.c
index fde1c49..b1dece6 100644

--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c

@@ -2671,7 +2671,10 @@ static int netvsc_suspend(struct hv_device *dev)

        /* Save the current config info */
        ndev_ctx->saved_netvsc_dev_info = netvsc_devinfo_get(nvdev);
-
+       if (!ndev_ctx->saved_netvsc_dev_info) {
+               ret = -ENOMEM;
+               goto out;
+       }
        ret = netvsc_detach(net, nvdev);
 out:
        rtnl_unlock();