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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, Tom Rix <trix@redhat.com>,
        Kalle Valo <kvalo@codeaurora.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 114/408] brcmfmac: check ndev pointer
Date:   Tue, 27 Oct 2020 14:50:52 +0100
Message-Id: <20201027135500.392022349@linuxfoundation.org>
In-Reply-To: <20201027135455.027547757@linuxfoundation.org>
References: <20201027135455.027547757@linuxfoundation.org>
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From: Tom Rix <trix@redhat.com>

[ Upstream commit 9c9f015bc9f8839831c7ba0a6d731a3853c464e2 ]

Clang static analysis reports this error

brcmfmac/core.c:490:4: warning: Dereference of null pointer
        (*ifp)->ndev->stats.rx_errors++;
        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

In this block of code

	if (ret || !(*ifp) || !(*ifp)->ndev) {
		if (ret != -ENODATA && *ifp)
			(*ifp)->ndev->stats.rx_errors++;
		brcmu_pkt_buf_free_skb(skb);
		return -ENODATA;
	}

(*ifp)->ndev being NULL is caught as an error
But then it is used to report the error.

So add a check before using it.

Fixes: 91b632803ee4 ("brcmfmac: Use net_device_stats from struct net_device")
Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200802161804.6126-1-trix@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
index 85cf96461ddeb..e9bb8dbdc9aa8 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
@@ -483,7 +483,7 @@ static int brcmf_rx_hdrpull(struct brcmf_pub *drvr, struct sk_buff *skb,
 	ret = brcmf_proto_hdrpull(drvr, true, skb, ifp);
 
 	if (ret || !(*ifp) || !(*ifp)->ndev) {
-		if (ret != -ENODATA && *ifp)
+		if (ret != -ENODATA && *ifp && (*ifp)->ndev)
 			(*ifp)->ndev->stats.rx_errors++;
 		brcmu_pkt_buf_free_skb(skb);
 		return -ENODATA;
-- 
2.25.1