Re: [PATCH nf] netfilter: nf_tables: fix oops when inserting an element into a verdict map

[Pablo Neira Ayuso <pablo@netfilter.org>]

On Sun, Nov 06, 2016 at 02:40:01PM +0800, Liping Zhang wrote:
> From: Liping Zhang <zlpnobody@gmail.com>
> 
> 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.

Applied, thanks for fixing up this, that was fast.