From: Pablo Neira Ayuso pablo@netfilter.org

stable inclusion from stable-v5.10.202 commit d9c4da8cb74e8ee6e58a064a3573aa37acf6c935 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I9DZOS

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...

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commit 179d9ba5559a756f4322583388b3213fe4e391b0 upstream.

The dormant flag need to be updated from the preparation phase, otherwise, two consecutive requests to dorm a table in the same batch might try to remove the same hooks twice, resulting in the following warning:

hook not found, pf 3 num 0 WARNING: CPU: 0 PID: 334 at net/netfilter/core.c:480 __nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480 Modules linked in: CPU: 0 PID: 334 Comm: kworker/u4:5 Not tainted 5.12.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:__nf_unregister_net_hook+0x1eb/0x610 net/netfilter/core.c:480

This patch is a partial revert of 0ce7cf4127f1 ("netfilter: nftables: update table flags from the commit phase") to restore the previous behaviour.

However, there is still another problem: A batch containing a series of dorm-wakeup-dorm table and vice-versa also trigger the warning above since hook unregistration happens from the preparation phase, while hook registration occurs from the commit phase.

To fix this problem, this patch adds two internal flags to annotate the original dormant flag status which are __NFT_TABLE_F_WAS_DORMANT and __NFT_TABLE_F_WAS_AWAKEN, to restore it from the abort path.

The __NFT_TABLE_F_UPDATE bitmask allows to handle the dormant flag update with one single transaction.

Reported-by: syzbot+7ad5cd1615f2d89c6e7e@syzkaller.appspotmail.com Fixes: 0ce7cf4127f1 ("netfilter: nftables: update table flags from the commit phase") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: sanglipeng sanglipeng1@jd.com Signed-off-by: dinglongwei dinglongwei1@huawei.com --- include/net/netfilter/nf_tables.h | 6 --- include/uapi/linux/netfilter/nf_tables.h | 1 + net/netfilter/nf_tables_api.c | 59 ++++++++++++++++-------- 3 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 8f749a59ff07..fb68e27064e4 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1501,16 +1501,10 @@ struct nft_trans_chain {

struct nft_trans_table { bool update; - u8 state; - u32 flags; };

#define nft_trans_table_update(trans) \ (((struct nft_trans_table *)trans->data)->update) -#define nft_trans_table_state(trans) \ - (((struct nft_trans_table *)trans->data)->state) -#define nft_trans_table_flags(trans) \ - (((struct nft_trans_table *)trans->data)->flags)

struct nft_trans_elem { struct nft_set *set; diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 98272cb5f617..6e7330ee573a 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -165,6 +165,7 @@ enum nft_hook_attributes { enum nft_table_flags { NFT_TABLE_F_DORMANT = 0x1, }; +#define NFT_TABLE_F_MASK (NFT_TABLE_F_DORMANT)

/** * enum nft_table_attributes - nf_tables table netlink attributes diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index cf50b19b333b..33ad3011716b 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -845,7 +845,8 @@ static int nf_tables_fill_table_info(struct sk_buff *skb, struct net *net, goto nla_put_failure;

if (nla_put_string(skb, NFTA_TABLE_NAME, table->name) || - nla_put_be32(skb, NFTA_TABLE_FLAGS, htonl(table->flags)) || + nla_put_be32(skb, NFTA_TABLE_FLAGS, + htonl(table->flags & NFT_TABLE_F_MASK)) || nla_put_be32(skb, NFTA_TABLE_USE, htonl(table->use)) || nla_put_be64(skb, NFTA_TABLE_HANDLE, cpu_to_be64(table->handle), NFTA_TABLE_PAD)) @@ -1053,20 +1054,22 @@ static int nf_tables_table_enable(struct net *net, struct nft_table *table)

static void nf_tables_table_disable(struct net *net, struct nft_table *table) { + table->flags &= ~NFT_TABLE_F_DORMANT; nft_table_disable(net, table, 0); + table->flags |= NFT_TABLE_F_DORMANT; }

-enum { - NFT_TABLE_STATE_UNCHANGED = 0, - NFT_TABLE_STATE_DORMANT, - NFT_TABLE_STATE_WAKEUP -}; +#define __NFT_TABLE_F_INTERNAL (NFT_TABLE_F_MASK + 1) +#define __NFT_TABLE_F_WAS_DORMANT (__NFT_TABLE_F_INTERNAL << 0) +#define __NFT_TABLE_F_WAS_AWAKEN (__NFT_TABLE_F_INTERNAL << 1) +#define __NFT_TABLE_F_UPDATE (__NFT_TABLE_F_WAS_DORMANT | \ + __NFT_TABLE_F_WAS_AWAKEN)

static int nf_tables_updtable(struct nft_ctx *ctx) { struct nft_trans *trans; u32 flags; - int ret = 0; + int ret;

if (!ctx->nla[NFTA_TABLE_FLAGS]) return 0; @@ -1085,21 +1088,27 @@ static int nf_tables_updtable(struct nft_ctx *ctx)

if ((flags & NFT_TABLE_F_DORMANT) && !(ctx->table->flags & NFT_TABLE_F_DORMANT)) { - nft_trans_table_state(trans) = NFT_TABLE_STATE_DORMANT; + ctx->table->flags |= NFT_TABLE_F_DORMANT; + if (!(ctx->table->flags & __NFT_TABLE_F_UPDATE)) + ctx->table->flags |= __NFT_TABLE_F_WAS_AWAKEN; } else if (!(flags & NFT_TABLE_F_DORMANT) && ctx->table->flags & NFT_TABLE_F_DORMANT) { - ret = nf_tables_table_enable(ctx->net, ctx->table); - if (ret >= 0) - nft_trans_table_state(trans) = NFT_TABLE_STATE_WAKEUP; + ctx->table->flags &= ~NFT_TABLE_F_DORMANT; + if (!(ctx->table->flags & __NFT_TABLE_F_UPDATE)) { + ret = nf_tables_table_enable(ctx->net, ctx->table); + if (ret < 0) + goto err_register_hooks; + + ctx->table->flags |= __NFT_TABLE_F_WAS_DORMANT; + } } - if (ret < 0) - goto err;

- nft_trans_table_flags(trans) = flags; nft_trans_table_update(trans) = true; nft_trans_commit_list_add_tail(ctx->net, trans); + return 0; -err: + +err_register_hooks: nft_trans_destroy(trans); return ret; } @@ -8242,10 +8251,14 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) switch (trans->msg_type) { case NFT_MSG_NEWTABLE: if (nft_trans_table_update(trans)) { - if (nft_trans_table_state(trans) == NFT_TABLE_STATE_DORMANT) + if (!(trans->ctx.table->flags & __NFT_TABLE_F_UPDATE)) { + nft_trans_destroy(trans); + break; + } + if (trans->ctx.table->flags & NFT_TABLE_F_DORMANT) nf_tables_table_disable(net, trans->ctx.table);

- trans->ctx.table->flags = nft_trans_table_flags(trans); + trans->ctx.table->flags &= ~__NFT_TABLE_F_UPDATE; } else { nft_clear(net, trans->ctx.table); } @@ -8461,9 +8474,17 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) switch (trans->msg_type) { case NFT_MSG_NEWTABLE: if (nft_trans_table_update(trans)) { - if (nft_trans_table_state(trans) == NFT_TABLE_STATE_WAKEUP) + if (!(trans->ctx.table->flags & __NFT_TABLE_F_UPDATE)) { + nft_trans_destroy(trans); + break; + } + if (trans->ctx.table->flags & __NFT_TABLE_F_WAS_DORMANT) { nf_tables_table_disable(net, trans->ctx.table); - + trans->ctx.table->flags |= NFT_TABLE_F_DORMANT; + } else if (trans->ctx.table->flags & __NFT_TABLE_F_WAS_AWAKEN) { + trans->ctx.table->flags &= ~NFT_TABLE_F_DORMANT; + } + trans->ctx.table->flags &= ~__NFT_TABLE_F_UPDATE; nft_trans_destroy(trans); } else { list_del_rcu(&trans->ctx.table->list);