net: rmnet_data: Fix incorrect netlink handling
rmnet_data netlink handler currently does not check for the
incoming process pid and instead just loops back the pid.
A malicious root user could potentially send a message with
source pid 0 and this could cause rmnet_data to loop the message
back till an out of memory situation occurs.
rmnet_data also does not check for the message length of the
incoming netlink messages and instead casts the netlink message
without checking for the boundary.
Fix these two scenarios by adding the pid and message length checks
respectively
Bug: 31252965
CRs-Fixed: 1098801
Change-Id: I172c1a7112e67e82959b397af7ddfd963d819bdc
Signed-off-by: Conner Huff <chuff@codeaurora.org>
diff --git a/net/rmnet_data/rmnet_data_config.c b/net/rmnet_data/rmnet_data_config.c
index 8eab5ae..f82676d 100644
--- a/net/rmnet_data/rmnet_data_config.c
+++ b/net/rmnet_data/rmnet_data_config.c
@@ -1,4 +1,4 @@
-/* Copyright (c) 2013-2016, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2013-2017, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
@@ -557,6 +557,11 @@
nlmsg_header = (struct nlmsghdr *)skb->data;
rmnet_header = (struct rmnet_nl_msg_s *)nlmsg_data(nlmsg_header);
+ if (!nlmsg_header->nlmsg_pid ||
+ (nlmsg_header->nlmsg_len < sizeof(struct nlmsghdr) +
+ sizeof(struct rmnet_nl_msg_s)))
+ return;
+
LOGL("Netlink message pid=%d, seq=%d, length=%d, rmnet_type=%d",
nlmsg_header->nlmsg_pid,
nlmsg_header->nlmsg_seq,