2016-12-20 21:09:12

by Sudip Mukherjee

Subject: [PATCH] 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 <[email protected]>
---
drivers/nfc/fdp/i2c.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/nfc/fdp/i2c.c b/drivers/nfc/fdp/i2c.c
index 5e797d5..712936f 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)
--
1.9.1

2017-04-01 22:37:09

by Samuel Ortiz

Subject: Re: [PATCH] nfc: fdp: fix NULL pointer dereference

Hi Sudip,

On Tue, Dec 20, 2016 at 09:09:04PM +0000, Sudip Mukherjee wrote:
> 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 <[email protected]>
> ---
> drivers/nfc/fdp/i2c.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
Applied to nfc-next, thanks.

Cheers,
Samuel.