This is a note to let you know that I've just added the patch titled nfc: fdp: fix NULL pointer dereference to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfc-fdp-fix-null-pointer-dereference.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From b6355fb3f5f40bbce165847d277e64896cab8f95 Mon Sep 17 00:00:00 2001 From: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> Date: Tue, 20 Dec 2016 21:09:04 +0000 Subject: nfc: fdp: fix NULL pointer dereference From: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx> commit b6355fb3f5f40bbce165847d277e64896cab8f95 upstream. 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@xxxxxxxxxxxxxxx> Signed-off-by: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/nfc/fdp/i2c.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/nfc/fdp/i2c.c +++ b/drivers/nfc/fdp/i2c.c @@ -210,14 +210,14 @@ static irqreturn_t fdp_nci_i2c_irq_threa 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) Patches currently in stable-queue which might be from sudipm.mukherjee@xxxxxxxxx are queue-4.9/nfc-fdp-fix-null-pointer-dereference.patch