From: Dmitry Vyukov dvyukov@google.com
This patch has been added to the 4.1 stable tree. If you have any objections, please let us know.
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[ Upstream commit 1a38956cce5eabd7b74f94bab70265e4df83165e ]
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: Sasha Levin alexander.levin@microsoft.com --- net/ipv4/netfilter/ipt_CLUSTERIP.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/netfilter/ipt_CLUSTERIP.c b/net/ipv4/netfilter/ipt_CLUSTERIP.c index 771ab3d01ad3..d098013855f0 100644 --- a/net/ipv4/netfilter/ipt_CLUSTERIP.c +++ b/net/ipv4/netfilter/ipt_CLUSTERIP.c @@ -365,7 +365,7 @@ static int clusterip_tg_check(const struct xt_tgchk_param *par) 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 (cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP && cipinfo->hash_mode != CLUSTERIP_HASHMODE_SIP_SPT && @@ -379,8 +379,18 @@ static int clusterip_tg_check(const struct xt_tgchk_param *par) 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) {