@@ -431,7 +431,7 @@ 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 (par->nft_compat) {
pr_err("cannot use CLUSTERIP target from nftables compat\n");
@@ -450,8 +450,18 @@ 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) {
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. Signed-off-by: Dmitry Vyukov <dvyukov@google.com> Fixes: 136e92bbec0a ("[NETFILTER] CLUSTERIP: use a bitmap to store node responsibility data") Reported-by: syzbot <syzkaller@googlegroups.com> Cc: netfilter-devel@vger.kernel.org Cc: coreteam@netfilter.org Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Cc: syzkaller@googlegroups.com --- net/ipv4/netfilter/ipt_CLUSTERIP.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)