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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, Tong Zhang <ztong0001@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 16/72] atm: idt77252: fix null-ptr-dereference
Date:   Mon, 29 Mar 2021 09:57:52 +0200
Message-Id: <20210329075610.818747128@linuxfoundation.org>
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From: Tong Zhang <ztong0001@gmail.com>

[ Upstream commit 4416e98594dc04590ebc498fc4e530009535c511 ]

this one is similar to the phy_data allocation fix in uPD98402, the
driver allocate the idt77105_priv and store to dev_data but later
dereference using dev->dev_data, which will cause null-ptr-dereference.

fix this issue by changing dev_data to phy_data so that PRIV(dev) can
work correctly.

Signed-off-by: Tong Zhang <ztong0001@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/atm/idt77105.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/atm/idt77105.c b/drivers/atm/idt77105.c
index 0a67487c0b1d..a2ecb4190f78 100644
--- a/drivers/atm/idt77105.c
+++ b/drivers/atm/idt77105.c
@@ -261,7 +261,7 @@ static int idt77105_start(struct atm_dev *dev)
 {
 	unsigned long flags;
 
-	if (!(dev->dev_data = kmalloc(sizeof(struct idt77105_priv),GFP_KERNEL)))
+	if (!(dev->phy_data = kmalloc(sizeof(struct idt77105_priv),GFP_KERNEL)))
 		return -ENOMEM;
 	PRIV(dev)->dev = dev;
 	spin_lock_irqsave(&idt77105_priv_lock, flags);
@@ -336,7 +336,7 @@ static int idt77105_stop(struct atm_dev *dev)
                 else
                     idt77105_all = walk->next;
 	        dev->phy = NULL;
-                dev->dev_data = NULL;
+                dev->phy_data = NULL;
                 kfree(walk);
                 break;
             }
-- 
2.30.1