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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, "David S. Miller" <davem@davemloft.net>,
        Dominik Brodowski <linux@dominikbrodowski.net>,
        Anirudh Rayabharam <mail@anirudhrb.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.12 168/296] net: fujitsu: fix potential null-ptr-deref
Date:   Mon, 31 May 2021 15:13:43 +0200
Message-Id: <20210531130709.515440493@linuxfoundation.org>
In-Reply-To: <20210531130703.762129381@linuxfoundation.org>
References: <20210531130703.762129381@linuxfoundation.org>
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From: Anirudh Rayabharam <mail@anirudhrb.com>

[ Upstream commit 52202be1cd996cde6e8969a128dc27ee45a7cb5e ]

In fmvj18x_get_hwinfo(), if ioremap fails there will be NULL pointer
deref. To fix this, check the return value of ioremap and return -1
to the caller in case of failure.

Cc: "David S. Miller" <davem@davemloft.net>
Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Anirudh Rayabharam <mail@anirudhrb.com>
Link: https://lore.kernel.org/r/20210503115736.2104747-16-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/fujitsu/fmvj18x_cs.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/fujitsu/fmvj18x_cs.c b/drivers/net/ethernet/fujitsu/fmvj18x_cs.c
index dc90c61fc827..b0c0504950d8 100644
--- a/drivers/net/ethernet/fujitsu/fmvj18x_cs.c
+++ b/drivers/net/ethernet/fujitsu/fmvj18x_cs.c
@@ -547,6 +547,11 @@ static int fmvj18x_get_hwinfo(struct pcmcia_device *link, u_char *node_id)
 	return -1;
 
     base = ioremap(link->resource[2]->start, resource_size(link->resource[2]));
+    if (!base) {
+	pcmcia_release_window(link, link->resource[2]);
+	return -1;
+    }
+
     pcmcia_map_mem_page(link, link->resource[2], 0);
 
     /*
-- 
2.30.2