4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Cong Wang <xiyou.wangcong@xxxxxxxxx>
commit ba7cd5d95f25cc6005f687dabdb4e7a6063adda9 upstream.
xt_cgroup_info_v1->priv is an internal pointer only used for kernel,
we should not trust what user-space provides.
Reported-by: <syzbot+4fbcfcc0d2e6592bd641@xxxxxxxxxxxxxxxxxxxxxxxxx>
Fixes: c38c4597e4bf ("netfilter: implement xt_cgroup cgroup2 path match")
Cc: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Cong Wang <xiyou.wangcong@xxxxxxxxx>
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/netfilter/xt_cgroup.c | 1 +
1 file changed, 1 insertion(+)
--- a/net/netfilter/xt_cgroup.c
+++ b/net/netfilter/xt_cgroup.c
@@ -52,6 +52,7 @@ static int cgroup_mt_check_v1(const stru
return -EINVAL;
}
+ info->priv = NULL;
if (info->has_path) {
cgrp = cgroup_get_from_path(info->path);
if (IS_ERR(cgrp)) {