[Devel] [PATCH 6/7] ms/netfilter: account ebt_table_info to kmemcg

[Alexander Mikhalitsyn]

From: Kirill Tkhai <ktkhai at virtuozzo.com>

[This is not in ms kernel yet, but we are not interested in waiting
 for next iteration (comment changing was reuested).
 https://lkml.org/lkml/2018/12/28/457]

The [ip,ip6,arp]_tables use x_tables_info internally and the underlying
memory is already accounted to kmemcg. Do the same for ebtables. The
syzbot, by using setsockopt(EBT_SO_SET_ENTRIES), was able to OOM the
whole system from a restricted memcg, a potential DoS.

Reported-by: syzbot+7713f3aa67be76b1552c at syzkaller.appspotmail.com
Signed-off-by: Shakeel Butt <shakeelb at google.com>
Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
(cherry picked from commit 93ffc59d9f9e8b65ad2bdfe090b56839f0a40411)

VZ 8 rebase part https://jira.sw.ru/browse/PSBM-127837

Signed-off-by: Alexander Mikhalitsyn <alexander.mikhalitsyn at virtuozzo.com>
---
 net/bridge/netfilter/ebtables.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
index bb8f9e816fb9..be24fff3ab3e 100644
--- a/net/bridge/netfilter/ebtables.c
+++ b/net/bridge/netfilter/ebtables.c
@@ -1132,14 +1132,16 @@ static int do_replace(struct net *net, const void __user *user,
 	tmp.name[sizeof(tmp.name) - 1] = 0;
 
 	countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids;
-	newinfo = vmalloc(sizeof(*newinfo) + countersize);
+	newinfo = __vmalloc(sizeof(*newinfo) + countersize, GFP_KERNEL_ACCOUNT,
+			    PAGE_KERNEL);
 	if (!newinfo)
 		return -ENOMEM;
 
 	if (countersize)
 		memset(newinfo->counters, 0, countersize);
 
-	newinfo->entries = vmalloc(tmp.entries_size);
+	newinfo->entries = __vmalloc(tmp.entries_size, GFP_KERNEL_ACCOUNT,
+				     PAGE_KERNEL);
 	if (!newinfo->entries) {
 		ret = -ENOMEM;
 		goto free_newinfo;
-- 
2.28.0