From: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Date: Tue, 20 Dec 2016 21:09:04 +0000 (+0000)
Subject: nfc: fdp: fix NULL pointer dereference
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=b6355fb3f5f40bbce165847d277e64896cab8f95;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

nfc: fdp: fix NULL pointer dereference

We are checking phy after dereferencing it. We can print the debug
information after checking it. If phy is NULL then we will get a good
stack trace to tell us that we are in this irq handler.

Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
---

diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c
index 5e797d5c38ed..712936f5d2d6 100644
--- a/drivers/nfc/fdp/i2c.c
+++ b/drivers/nfc/fdp/i2c.c
@@ -210,14 +210,14 @@ static irqreturn_t fdp_nci_i2c_irq_thread_fn(int irq, void *phy_id)
 	struct sk_buff *skb;
 	int r;
 
-	client = phy->i2c_dev;
-	dev_dbg(&client->dev, "%s\n", __func__);
-
 	if (!phy || irq != phy->i2c_dev->irq) {
 		WARN_ON_ONCE(1);
 		return IRQ_NONE;
 	}
 
+	client = phy->i2c_dev;
+	dev_dbg(&client->dev, "%s\n", __func__);
+
 	r = fdp_nci_i2c_read(phy, &skb);
 
 	if (r == -EREMOTEIO)