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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Yongzhi Liu <lyz_cs@pku.edu.cn>,
        Haiyang Zhang <haiyangz@microsoft.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.17 435/772] hv_netvsc: Fix potential dereference of NULL pointer
Date:   Tue,  7 Jun 2022 19:00:27 +0200
Message-Id: <20220607165001.821144219@linuxfoundation.org>
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From: Yongzhi Liu <lyz_cs@pku.edu.cn>

[ Upstream commit eb4c0788964730d12e8dd520bd8f5217ca48321c ]

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

Fixes: 0efeea5fb153 ("hv_netvsc: Add the support of hibernation")
Signed-off-by: Yongzhi Liu <lyz_cs@pku.edu.cn>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Link: https://lore.kernel.org/r/1652962188-129281-1-git-send-email-lyz_cs@pku.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 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 fde1c492ca02..b1dece6b9698 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();
-- 
2.35.1