Patch "nfc: Ensure presence of required attributes in the activate_target handler" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    nfc: Ensure presence of required attributes in the activate_target handler

to the 4.4-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-ensure-presence-of-required-attributes-in-the-activate_target-handler.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From a0323b979f81ad2deb2c8836eab506534891876a Mon Sep 17 00:00:00 2001
From: Mateusz Jurczyk <mjurczyk@google.com>
Date: Wed, 24 May 2017 12:42:26 +0200
Subject: nfc: Ensure presence of required attributes in the activate_target handler

From: Mateusz Jurczyk <mjurczyk@google.com>

commit a0323b979f81ad2deb2c8836eab506534891876a upstream.

Check that the NFC_ATTR_TARGET_INDEX and NFC_ATTR_PROTOCOLS attributes (in
addition to NFC_ATTR_DEVICE_INDEX) are provided by the netlink client
prior to accessing them. This prevents potential unhandled NULL pointer
dereference exceptions which can be triggered by malicious user-mode
programs, if they omit one or both of these attributes.

Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/nfc/netlink.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -873,7 +873,9 @@ static int nfc_genl_activate_target(stru
 	u32 device_idx, target_idx, protocol;
 	int rc;
 
-	if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
+	if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
+	    !info->attrs[NFC_ATTR_TARGET_INDEX] ||
+	    !info->attrs[NFC_ATTR_PROTOCOLS])
 		return -EINVAL;
 
 	device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);


Patches currently in stable-queue which might be from mjurczyk@google.com are

queue-4.4/nfc-add-sockaddr-length-checks-before-accessing-sa_family-in-bind-handlers.patch
queue-4.4/nfc-ensure-presence-of-required-attributes-in-the-activate_target-handler.patch
queue-4.4/nfc-fix-the-sockaddr-length-sanitization-in-llcp_sock_connect.patch