From 97840cb67ff5ac8add836684f011fd838518d698 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Fri, 14 Nov 2014 18:14:33 +0100 Subject: netfilter: nfnetlink: fix insufficient validation in nfnetlink_bind Make sure the netlink group exists, otherwise you can trigger an out of bound array memory access from the netlink_bind() path. This splat can only be triggered only by superuser. [ 180.203600] UBSan: Undefined behaviour in ../net/netfilter/nfnetlink.c:467:28 [ 180.204249] index 9 is out of range for type 'int [9]' [ 180.204697] CPU: 0 PID: 1771 Comm: trinity-main Not tainted 3.18.0-rc4-mm1+ #122 [ 180.205365] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org +04/01/2014 [ 180.206498] 0000000000000018 0000000000000000 0000000000000009 ffff88007bdf7da8 [ 180.207220] ffffffff82b0ef5f 0000000000000092 ffffffff845ae2e0 ffff88007bdf7db8 [ 180.207887] ffffffff8199e489 ffff88007bdf7e18 ffffffff8199ea22 0000003900000000 [ 180.208639] Call Trace: [ 180.208857] dump_stack (lib/dump_stack.c:52) [ 180.209370] ubsan_epilogue (lib/ubsan.c:174) [ 180.209849] __ubsan_handle_out_of_bounds (lib/ubsan.c:400) [ 180.210512] nfnetlink_bind (net/netfilter/nfnetlink.c:467) [ 180.210986] netlink_bind (net/netlink/af_netlink.c:1483) [ 180.211495] SYSC_bind (net/socket.c:1541) Moreover, define the missing nf_tables and nf_acct multicast groups too. Reported-by: Andrey Ryabinin Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nfnetlink.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 6c5a915cfa75..13c2e17bbe27 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -47,6 +47,8 @@ static const int nfnl_group2type[NFNLGRP_MAX+1] = { [NFNLGRP_CONNTRACK_EXP_NEW] = NFNL_SUBSYS_CTNETLINK_EXP, [NFNLGRP_CONNTRACK_EXP_UPDATE] = NFNL_SUBSYS_CTNETLINK_EXP, [NFNLGRP_CONNTRACK_EXP_DESTROY] = NFNL_SUBSYS_CTNETLINK_EXP, + [NFNLGRP_NFTABLES] = NFNL_SUBSYS_NFTABLES, + [NFNLGRP_ACCT_QUOTA] = NFNL_SUBSYS_ACCT, }; void nfnl_lock(__u8 subsys_id) @@ -464,7 +466,12 @@ static void nfnetlink_rcv(struct sk_buff *skb) static int nfnetlink_bind(int group) { const struct nfnetlink_subsystem *ss; - int type = nfnl_group2type[group]; + int type; + + if (group <= NFNLGRP_NONE || group > NFNLGRP_MAX) + return -EINVAL; + + type = nfnl_group2type[group]; rcu_read_lock(); ss = nfnetlink_get_subsys(type); @@ -514,6 +521,9 @@ static int __init nfnetlink_init(void) { int i; + for (i = NFNLGRP_NONE + 1; i <= NFNLGRP_MAX; i++) + BUG_ON(nfnl_group2type[i] == NFNL_SUBSYS_NONE); + for (i=0; i