From: Liping Zhang zlpnobody@gmail.com
commit 58c78e104d937c1f560fb10ed9bb2dcde0db4fcf upstream.
Dalegaard says: The following ruleset, when loaded with 'nft -f bad.txt' ----snip---- flush ruleset table ip inlinenat { map sourcemap { type ipv4_addr : verdict; }
chain postrouting { ip saddr vmap @sourcemap accept } } add chain inlinenat test add element inlinenat sourcemap { 100.123.10.2 : jump test } ----snip----
results in a kernel oops: BUG: unable to handle kernel paging request at 0000000000001344 IP: [<ffffffffa07bf704>] nf_tables_check_loops+0x114/0x1f0 [nf_tables] [...] Call Trace: [<ffffffffa07c2aae>] ? nft_data_init+0x13e/0x1a0 [nf_tables] [<ffffffffa07c1950>] nft_validate_register_store+0x60/0xb0 [nf_tables] [<ffffffffa07c74b5>] nft_add_set_elem+0x545/0x5e0 [nf_tables] [<ffffffffa07bfdd0>] ? nft_table_lookup+0x30/0x60 [nf_tables] [<ffffffff8132c630>] ? nla_strcmp+0x40/0x50 [<ffffffffa07c766e>] nf_tables_newsetelem+0x11e/0x210 [nf_tables] [<ffffffff8132c400>] ? nla_validate+0x60/0x80 [<ffffffffa030d9b4>] nfnetlink_rcv+0x354/0x5a7 [nfnetlink]
Because we forget to fill the net pointer in bind_ctx, so dereferencing it may cause kernel crash.
Reported-by: Dalegaard dalegaard@gmail.com Signed-off-by: Liping Zhang zlpnobody@gmail.com Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Amit Pundir amit.pundir@linaro.org --- net/netfilter/nf_tables_api.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 120e9ae04db3..a7967af0da82 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3452,6 +3452,7 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, dreg = nft_type_to_reg(set->dtype); list_for_each_entry(binding, &set->bindings, list) { struct nft_ctx bind_ctx = { + .net = ctx->net, .afi = ctx->afi, .table = ctx->table, .chain = (struct nft_chain *)binding->chain,