Commit a0323b97 authored May 24, 2017 by Mateusz Jurczyk Committed by Samuel Ortiz Jun 23, 2017

nfc: Ensure presence of required attributes in the activate_target handler



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>

parent 608c4adf

net/nfc/netlink.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -907,7 +907,9 @@ static int nfc_genl_activate_target(struct sk_buff skb, struct genl_info info)
		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]);