Unregister flowtable hooks before they are releases via
nf_tables_flowtable_destroy() otherwise hook core reports UAF.
BUG: KASAN: use-after-free in nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142
Read of size 4 at addr ffff8880736f7438 by task syz-executor579/3666
CPU: 0 PID: 3666 Comm: syz-executor579 Not tainted 5.16.0-rc5-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
__dump_stack lib/dump_stack.c:88 [inline] lib/dump_stack.c:106
dump_stack_lvl+0x1dc/0x2d8 lib/dump_stack.c:106 lib/dump_stack.c:106
print_address_description+0x65/0x380 mm/kasan/report.c:247 mm/kasan/report.c:247
__kasan_report mm/kasan/report.c:433 [inline]
__kasan_report mm/kasan/report.c:433 [inline] mm/kasan/report.c:450
kasan_report+0x19a/0x1f0 mm/kasan/report.c:450 mm/kasan/report.c:450
nf_hook_entries_grow+0x5a7/0x700 net/netfilter/core.c:142 net/netfilter/core.c:142
__nf_register_net_hook+0x27e/0x8d0 net/netfilter/core.c:429 net/netfilter/core.c:429
nf_register_net_hook+0xaa/0x180 net/netfilter/core.c:571 net/netfilter/core.c:571
nft_register_flowtable_net_hooks+0x3c5/0x730 net/netfilter/nf_tables_api.c:7232 net/netfilter/nf_tables_api.c:7232
nf_tables_newflowtable+0x2022/0x2cf0 net/netfilter/nf_tables_api.c:7430 net/netfilter/nf_tables_api.c:7430
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline]
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
nfnetlink_rcv_batch net/netfilter/nfnetlink.c:513 [inline] net/netfilter/nfnetlink.c:652
nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline] net/netfilter/nfnetlink.c:652
nfnetlink_rcv+0x10e6/0x2550 net/netfilter/nfnetlink.c:652 net/netfilter/nfnetlink.c:652
Fixes: ff4bf2f42a40 ("netfilter: nf_tables: add nft_unregister_flowtable_hook()")
Reported-by: syzbot+e918523f77e62790d6d9@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx>
---
net/netfilter/nf_tables_api.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 5fa16990da95..3081c4399f10 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -9636,10 +9636,13 @@ EXPORT_SYMBOL_GPL(__nft_release_basechain);
static void __nft_release_hook(struct net *net, struct nft_table *table)
{
+ struct nft_flowtable *flowtable;
struct nft_chain *chain;
list_for_each_entry(chain, &table->chains, list)
nf_tables_unregister_hook(net, table, chain);
+ list_for_each_entry(flowtable, &table->flowtables, list)
+ nft_unregister_flowtable_net_hooks(net, &flowtable->hook_list);
}
static void __nft_release_hooks(struct net *net)
--
2.30.2
