From 77972a36ecc4db7fc7c68f0e80714263c5f03f65 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 31 Aug 2022 13:11:47 +0200 Subject: [PATCH] netfilter: nf_tables: clean up hook list when offload flags check fails splice back the hook list so nft_chain_release_hook() has a chance to release the hooks. BUG: memory leak unreferenced object 0xffff88810180b100 (size 96): comm "syz-executor133", pid 3619, jiffies 4294945714 (age 12.690s) hex dump (first 32 bytes): 28 64 23 02 81 88 ff ff 28 64 23 02 81 88 ff ff (d#.....(d#..... 90 a8 aa 83 ff ff ff ff 00 00 b5 0f 81 88 ff ff ................ backtrace: [] kmalloc include/linux/slab.h:600 [inline] [] nft_netdev_hook_alloc+0x3b/0xc0 net/netfilter/nf_tables_api.c:1901 [] nft_chain_parse_netdev net/netfilter/nf_tables_api.c:1998 [inline] [] nft_chain_parse_hook+0x33a/0x530 net/netfilter/nf_tables_api.c:2073 [] nf_tables_addchain.constprop.0+0x10b/0x950 net/netfilter/nf_tables_api.c:2218 [] nf_tables_newchain+0xa8b/0xc60 net/netfilter/nf_tables_api.c:2593 [] nfnetlink_rcv_batch+0xa46/0xd20 net/netfilter/nfnetlink.c:517 [] nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:638 [inline] [] nfnetlink_rcv+0x1f9/0x220 net/netfilter/nfnetlink.c:656 [] netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] [] netlink_unicast+0x397/0x4c0 net/netlink/af_netlink.c:1345 [] netlink_sendmsg+0x396/0x710 net/netlink/af_netlink.c:1921 [] sock_sendmsg_nosec net/socket.c:714 [inline] [] sock_sendmsg+0x56/0x80 net/socket.c:734 [] ____sys_sendmsg+0x36c/0x390 net/socket.c:2482 [] ___sys_sendmsg+0xa8/0x110 net/socket.c:2536 [] __sys_sendmsg+0x88/0x100 net/socket.c:2565 [] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [] entry_SYSCALL_64_after_hwframe+0x63/0xcd Fixes: d54725cd11a5 ("netfilter: nf_tables: support for multiple devices per netdev hook") Reported-by: syzbot+5fcdbfab6d6744c57418@syzkaller.appspotmail.com Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 2ee50e2..81605208 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2166,8 +2166,10 @@ static int nft_basechain_init(struct nft_base_chain *basechain, u8 family, chain->flags |= NFT_CHAIN_BASE | flags; basechain->policy = NF_ACCEPT; if (chain->flags & NFT_CHAIN_HW_OFFLOAD && - !nft_chain_offload_support(basechain)) + !nft_chain_offload_support(basechain)) { + list_splice_init(&basechain->hook_list, &hook->list); return -EOPNOTSUPP; + } flow_block_init(&basechain->flow_block); -- 2.7.4