netfilter: nf_tables: reject new basechain after table flag update

commit 994209ddf4 upstream.

When dormant flag is toggled, hooks are disabled in the commit phase by
iterating over current chains in table (existing and new).

The following configuration allows for an inconsistent state:

  add table x
  add chain x y { type filter hook input priority 0; }
  add table x { flags dormant; }
  add chain x w { type filter hook input priority 1; }

which triggers the following warning when trying to unregister chain w
which is already unregistered.

[  127.322252] WARNING: CPU: 7 PID: 1211 at net/netfilter/core.c:50                                                                     1 __nf_unregister_net_hook+0x21a/0x260
[...]
[  127.322519] Call Trace:
[  127.322521]  <TASK>
[  127.322524]  ? __warn+0x9f/0x1a0
[  127.322531]  ? __nf_unregister_net_hook+0x21a/0x260
[  127.322537]  ? report_bug+0x1b1/0x1e0
[  127.322545]  ? handle_bug+0x3c/0x70
[  127.322552]  ? exc_invalid_op+0x17/0x40
[  127.322556]  ? asm_exc_invalid_op+0x1a/0x20
[  127.322563]  ? kasan_save_free_info+0x3b/0x60
[  127.322570]  ? __nf_unregister_net_hook+0x6a/0x260
[  127.322577]  ? __nf_unregister_net_hook+0x21a/0x260
[  127.322583]  ? __nf_unregister_net_hook+0x6a/0x260
[  127.322590]  ? __nf_tables_unregister_hook+0x8a/0xe0 [nf_tables]
[  127.322655]  nft_table_disable+0x75/0xf0 [nf_tables]
[  127.322717]  nf_tables_commit+0x2571/0x2620 [nf_tables]

Fixes: 179d9ba555 ("netfilter: nf_tables: fix table flag updates")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pablo Neira Ayuso 2024-04-01 00:33:02 +02:00 committed by Greg Kroah-Hartman
parent e40f32f176
commit 420132bee3

View File

@ -2439,6 +2439,9 @@ static int nf_tables_addchain(struct nft_ctx *ctx, u8 family, u8 genmask,
struct nft_stats __percpu *stats = NULL;
struct nft_chain_hook hook = {};
if (table->flags & __NFT_TABLE_F_UPDATE)
return -EINVAL;
if (flags & NFT_CHAIN_BINDING)
return -EOPNOTSUPP;