Patch "netfilter: ipt_CLUSTERIP: fix out-of-bounds accesses in clusterip_tg_check()" has been added to the 4.15-stable tree

[<gregkh@linuxfoundation.org>]

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

    netfilter: ipt_CLUSTERIP: fix out-of-bounds accesses in clusterip_tg_check()

to the 4.15-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:
     netfilter-ipt_clusterip-fix-out-of-bounds-accesses-in-clusterip_tg_check.patch
and it can be found in the queue-4.15 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 1a38956cce5eabd7b74f94bab70265e4df83165e Mon Sep 17 00:00:00 2001
From: Dmitry Vyukov <dvyukov@google.com>
Date: Tue, 30 Jan 2018 15:21:34 +0100
Subject: netfilter: ipt_CLUSTERIP: fix out-of-bounds accesses in clusterip_tg_check()

From: Dmitry Vyukov <dvyukov@google.com>

commit 1a38956cce5eabd7b74f94bab70265e4df83165e upstream.

Commit 136e92bbec0a switched local_nodes from an array to a bitmask
but did not add proper bounds checks. As the result
clusterip_config_init_nodelist() can both over-read
ipt_clusterip_tgt_info.local_nodes and over-write
clusterip_config.local_nodes.

Add bounds checks for both.

Fixes: 136e92bbec0a ("[NETFILTER] CLUSTERIP: use a bitmap to store node responsibility data")
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 net/ipv4/netfilter/ipt_CLUSTERIP.c |   16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

--- a/net/ipv4/netfilter/ipt_CLUSTERIP.c
+++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c
@@ -431,7 +431,7 @@ static int clusterip_tg_check(const stru
 	struct ipt_clusterip_tgt_info *cipinfo = par->targinfo;
 	const struct ipt_entry *e = par->entryinfo;
 	struct clusterip_config *config;
-	int ret;
+	int ret, i;
 
 	if (par->nft_compat) {
 		pr_err("cannot use CLUSTERIP target from nftables compat\n");
@@ -450,8 +450,18 @@ static int clusterip_tg_check(const stru
 		pr_info("Please specify destination IP\n");
 		return -EINVAL;
 	}
-
-	/* FIXME: further sanity checks */
+	if (cipinfo->num_local_nodes > ARRAY_SIZE(cipinfo->local_nodes)) {
+		pr_info("bad num_local_nodes %u\n", cipinfo->num_local_nodes);
+		return -EINVAL;
+	}
+	for (i = 0; i < cipinfo->num_local_nodes; i++) {
+		if (cipinfo->local_nodes[i] - 1 >=
+		    sizeof(config->local_nodes) * 8) {
+			pr_info("bad local_nodes[%d] %u\n",
+				i, cipinfo->local_nodes[i]);
+			return -EINVAL;
+		}
+	}
 
 	config = clusterip_config_find_get(par->net, e->ip.dst.s_addr, 1);
 	if (!config) {


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

queue-4.15/kvm-x86-fix-escape-of-guest-dr6-to-the-host.patch
queue-4.15/netfilter-x_tables-fix-int-overflow-in-xt_alloc_table_info.patch
queue-4.15/netfilter-ipt_clusterip-fix-out-of-bounds-accesses-in-clusterip_tg_check.patch
queue-4.15/kcov-detect-double-association-with-a-single-task.patch