From: Pablo Neira Ayuso <pablo@netfilter.org> mainline inclusion from mainline-v7.1-rc2 commit 10f79dbd7719d1da9f5884d13060322d8729f091 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16187 CVE: CVE-2026-63858 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- Restore the flag that indicates that the hook is going away, ie. NFT_HOOK_REMOVE, but add a new transaction object to track deletion of hooks without altering the basechain/flowtable hook_list during the preparation phase. The existing approach that moves the hook from the basechain/flowtable hook_list to transaction hook_list breaks netlink dump path readers of this RCU-protected list. It should be possible use an array for nft_trans_hook to store the deleted hooks to compact the representation but I am not expecting many hook object, specially now that wildcard support for devices is in place. Note that the nft_trans_chain_hooks() list contains a list of struct nft_trans_hook objects for DELCHAIN and DELFLOWTABLE commands, while this list stores struct nft_hook objects for NEWCHAIN and NEWFLOWTABLE. Note that new commands can be updated to use nft_trans_hook for consistency. This patch also adapts the event notification path to deal with the list of hook transactions. Fixes: 7d937b107108 ("netfilter: nf_tables: support for deleting devices in an existing netdev chain") Fixes: b6d9014a3335 ("netfilter: nf_tables: delete flowtable hooks via transaction list") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Conflicts: include/net/netfilter/nf_tables.h net/netfilter/nf_tables_api.c [-commit b7c2d793c28cd, 880ccec0d02e and 4039ce7ef404 that introduce nft_nla_put_hook_dev() are not backport. use nla_put_string to adapt. -commit 3567146b94af add net param and lockdep to nft_dump_basechain_hook. -commit a1050dd07168 add event check in nf_tables_fill_chain_info. Its no need to add redundant hook list check for nft_dump_basechain_hook. -commit 2932ba8d9c99 that introduce kmalloc_obj is not backport. we still use kmalloc for hook -73319a8ee18b9 introduce ops_list to nft_hook, which is not backport -91a089d0569d Pass nf_hook_ops to nft_unregister_flowtable_hook(), which is not backport. -e169285f8c56b that move net,seq from nft_ctx to trans is not backport] Signed-off-by: Dong Chenchen <dongchenchen2@huawei.com> --- include/net/netfilter/nf_tables.h | 13 ++ net/netfilter/nf_tables_api.c | 252 +++++++++++++++++++++++------- 2 files changed, 209 insertions(+), 56 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index df8af10136da..6de207b6d6e6 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -1207,10 +1207,13 @@ struct nft_stats { struct u64_stats_sync syncp; }; +#define NFT_HOOK_REMOVE (1 << 0) + struct nft_hook { struct list_head list; struct nf_hook_ops ops; struct rcu_head rcu; + u8 flags; }; /** @@ -1645,6 +1648,16 @@ struct nft_trans { char data[]; }; +/** + * struct nft_trans_hook - nf_tables hook update in transaction + * @list: used internally + * @hook: struct nft_hook with the device hook + */ +struct nft_trans_hook { + struct list_head list; + struct nft_hook *hook; +}; + struct nft_trans_rule { struct nft_rule *rule; struct nft_flow_rule *flow; diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 3c98d088857a..696b053522f0 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -339,6 +339,30 @@ static void nft_netdev_hook_unlink_free_rcu(struct nft_hook *hook) nft_netdev_hook_free_rcu(hook); } +static void nft_trans_hook_destroy(struct nft_trans_hook *trans_hook) +{ + list_del(&trans_hook->list); + kfree(trans_hook); +} + +static void nft_netdev_unregister_trans_hook(struct net *net, + const struct nft_table *table, + struct list_head *hook_list) +{ + struct nft_trans_hook *trans_hook, *next; + struct nft_hook *hook; + + list_for_each_entry_safe(trans_hook, next, hook_list, list) { + hook = trans_hook->hook; + + if (!(table->flags & NFT_TABLE_F_DORMANT)) + nf_unregister_net_hook(net, &hook->ops); + + nft_netdev_hook_unlink_free_rcu(hook); + nft_trans_hook_destroy(trans_hook); + } +} + static void nft_netdev_unregister_hooks(struct net *net, struct list_head *hook_list, bool release_netdev) @@ -1791,14 +1815,66 @@ static int nft_dump_stats(struct sk_buff *skb, struct nft_stats __percpu *stats) return -ENOSPC; } +struct nft_hook_dump_ctx { + struct nft_hook *first; + int n; +}; + +static int nft_dump_basechain_hook_one(struct sk_buff *skb, + struct nft_hook *hook, + struct nft_hook_dump_ctx *dump_ctx) +{ + if (!dump_ctx->first) + dump_ctx->first = hook; + + if (nla_put_string(skb, NFTA_DEVICE_NAME, hook->ops.dev->name)) + return -1; + + dump_ctx->n++; + + return 0; +} + +static int nft_dump_basechain_hook_list(struct sk_buff *skb, + const struct list_head *hook_list, + struct nft_hook_dump_ctx *dump_ctx) +{ + struct nft_hook *hook; + int err; + + list_for_each_entry_rcu(hook, hook_list, list) { + err = nft_dump_basechain_hook_one(skb, hook, dump_ctx); + if (err < 0) + return err; + } + + return 0; +} + +static int nft_dump_basechain_trans_hook_list(struct sk_buff *skb, + const struct list_head *trans_hook_list, + struct nft_hook_dump_ctx *dump_ctx) +{ + struct nft_trans_hook *trans_hook; + int err; + + list_for_each_entry(trans_hook, trans_hook_list, list) { + err = nft_dump_basechain_hook_one(skb, trans_hook->hook, dump_ctx); + if (err < 0) + return err; + } + + return 0; +} + static int nft_dump_basechain_hook(struct sk_buff *skb, int family, const struct nft_base_chain *basechain, - const struct list_head *hook_list) + const struct list_head *hook_list, + const struct list_head *trans_hook_list) { const struct nf_hook_ops *ops = &basechain->ops; - struct nft_hook *hook, *first = NULL; + struct nft_hook_dump_ctx dump_hook_ctx = {}; struct nlattr *nest, *nest_devs; - int n = 0; nest = nla_nest_start_noflag(skb, NFTA_CHAIN_HOOK); if (nest == NULL) @@ -1813,22 +1889,22 @@ static int nft_dump_basechain_hook(struct sk_buff *skb, int family, if (!nest_devs) goto nla_put_failure; - if (!hook_list) + if (!hook_list && !trans_hook_list) hook_list = &basechain->hook_list; - list_for_each_entry_rcu(hook, hook_list, list) { - if (!first) - first = hook; - - if (nla_put_string(skb, NFTA_DEVICE_NAME, - hook->ops.dev->name)) - goto nla_put_failure; - n++; + if (hook_list && + nft_dump_basechain_hook_list(skb, hook_list, &dump_hook_ctx)) { + goto nla_put_failure; + } else if (trans_hook_list && + nft_dump_basechain_trans_hook_list(skb, trans_hook_list, + &dump_hook_ctx)) { + goto nla_put_failure; } + nla_nest_end(skb, nest_devs); - if (n == 1 && - nla_put_string(skb, NFTA_HOOK_DEV, first->ops.dev->name)) + if (dump_hook_ctx.n == 1 && + nla_put_string(skb, NFTA_HOOK_DEV, dump_hook_ctx.first->ops.dev->name)) goto nla_put_failure; } nla_nest_end(skb, nest); @@ -1842,7 +1918,8 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, u32 portid, u32 seq, int event, u32 flags, int family, const struct nft_table *table, const struct nft_chain *chain, - const struct list_head *hook_list) + const struct list_head *hook_list, + const struct list_head *trans_hook_list) { struct nlmsghdr *nlh; @@ -1862,7 +1939,8 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, const struct nft_base_chain *basechain = nft_base_chain(chain); struct nft_stats __percpu *stats; - if (nft_dump_basechain_hook(skb, family, basechain, hook_list)) + if (nft_dump_basechain_hook(skb, family, basechain, + hook_list, trans_hook_list)) goto nla_put_failure; if (nla_put_be32(skb, NFTA_CHAIN_POLICY, @@ -1898,7 +1976,8 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net, } static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event, - const struct list_head *hook_list) + const struct list_head *hook_list, + const struct list_head *trans_hook_list) { struct nftables_pernet *nft_net; struct sk_buff *skb; @@ -1918,7 +1997,7 @@ static void nf_tables_chain_notify(const struct nft_ctx *ctx, int event, err = nf_tables_fill_chain_info(skb, ctx->net, ctx->portid, ctx->seq, event, flags, ctx->family, ctx->table, - ctx->chain, hook_list); + ctx->chain, hook_list, trans_hook_list); if (err < 0) { kfree_skb(skb); goto err; @@ -1964,7 +2043,7 @@ static int nf_tables_dump_chains(struct sk_buff *skb, NFT_MSG_NEWCHAIN, NLM_F_MULTI, table->family, table, - chain, NULL) < 0) + chain, NULL, NULL) < 0) goto done; nl_dump_check_consistent(cb, nlmsg_hdr(skb)); @@ -2018,7 +2097,7 @@ static int nf_tables_getchain(struct sk_buff *skb, const struct nfnl_info *info, err = nf_tables_fill_chain_info(skb2, net, NETLINK_CB(skb).portid, info->nlh->nlmsg_seq, NFT_MSG_NEWCHAIN, - 0, family, table, chain, NULL); + 0, family, table, chain, NULL, NULL); if (err < 0) goto err_fill_chain_info; @@ -2168,8 +2247,12 @@ static struct nft_hook *nft_hook_list_find(struct list_head *hook_list, struct nft_hook *hook; list_for_each_entry(hook, hook_list, list) { - if (this->ops.dev == hook->ops.dev) + if (this->ops.dev == hook->ops.dev) { + if (hook->flags & NFT_HOOK_REMOVE) + continue; + return hook; + } } return NULL; @@ -2917,6 +3000,32 @@ static int nf_tables_newchain(struct sk_buff *skb, const struct nfnl_info *info, return nf_tables_addchain(&ctx, family, genmask, policy, flags, extack); } +static int nft_trans_delhook(struct nft_hook *hook, + struct list_head *del_list) +{ + struct nft_trans_hook *trans_hook; + + trans_hook = kmalloc(sizeof(*trans_hook), GFP_KERNEL); + if (!trans_hook) + return -ENOMEM; + + trans_hook->hook = hook; + list_add_tail(&trans_hook->list, del_list); + hook->flags |= NFT_HOOK_REMOVE; + + return 0; +} + +static void nft_trans_delhook_abort(struct list_head *del_list) +{ + struct nft_trans_hook *trans_hook, *next; + + list_for_each_entry_safe(trans_hook, next, del_list, list) { + trans_hook->hook->flags &= ~NFT_HOOK_REMOVE; + nft_trans_hook_destroy(trans_hook); + } +} + static int nft_delchain_hook(struct nft_ctx *ctx, struct nft_base_chain *basechain, struct netlink_ext_ack *extack) @@ -2943,7 +3052,10 @@ static int nft_delchain_hook(struct nft_ctx *ctx, err = -ENOENT; goto err_chain_del_hook; } - list_move(&hook->list, &chain_del_list); + if (nft_trans_delhook(hook, &chain_del_list) < 0) { + err = -ENOMEM; + goto err_chain_del_hook; + } } trans = nft_trans_alloc(ctx, NFT_MSG_DELCHAIN, @@ -2964,7 +3076,7 @@ static int nft_delchain_hook(struct nft_ctx *ctx, return 0; err_chain_del_hook: - list_splice(&chain_del_list, &basechain->hook_list); + nft_trans_delhook_abort(&chain_del_list); nft_chain_release_hook(&chain_hook); return err; @@ -8572,6 +8684,22 @@ static void nft_hooks_destroy(struct list_head *hook_list) nft_netdev_hook_unlink_free_rcu(hook); } +static void nft_flowtable_unregister_trans_hook(struct net *net, + struct nft_flowtable *flowtable, + struct list_head *hook_list) +{ + struct nft_trans_hook *trans_hook, *next; + struct nft_hook *hook; + + list_for_each_entry_safe(trans_hook, next, hook_list, list) { + hook = trans_hook->hook; + + nft_unregister_flowtable_hook(net, flowtable, hook); + nft_netdev_hook_unlink_free_rcu(hook); + nft_trans_hook_destroy(trans_hook); + } +} + static int nft_flowtable_update(struct nft_ctx *ctx, const struct nlmsghdr *nlh, struct nft_flowtable *flowtable, struct netlink_ext_ack *extack) @@ -8826,7 +8954,10 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx, err = -ENOENT; goto err_flowtable_del_hook; } - list_move(&hook->list, &flowtable_del_list); + if (nft_trans_delhook(hook, &flowtable_del_list) < 0) { + err = -ENOMEM; + goto err_flowtable_del_hook; + } } trans = nft_trans_alloc(ctx, NFT_MSG_DELFLOWTABLE, @@ -8847,7 +8978,7 @@ static int nft_delflowtable_hook(struct nft_ctx *ctx, return 0; err_flowtable_del_hook: - list_splice(&flowtable_del_list, &flowtable->hook_list); + nft_trans_delhook_abort(&flowtable_del_list); nft_flowtable_hook_release(&flowtable_hook); return err; @@ -8912,8 +9043,10 @@ static int nf_tables_fill_flowtable_info(struct sk_buff *skb, struct net *net, u32 portid, u32 seq, int event, u32 flags, int family, struct nft_flowtable *flowtable, - struct list_head *hook_list) + struct list_head *hook_list, + struct list_head *trans_hook_list) { + struct nft_trans_hook *trans_hook; struct nlattr *nest, *nest_devs; struct nft_hook *hook; struct nlmsghdr *nlh; @@ -8945,12 +9078,21 @@ static int nf_tables_fill_flowtable_info(struct sk_buff *skb, struct net *net, if (!nest_devs) goto nla_put_failure; - if (!hook_list) + if (!hook_list && !trans_hook_list) hook_list = &flowtable->hook_list; - list_for_each_entry_rcu(hook, hook_list, list) { - if (nla_put_string(skb, NFTA_DEVICE_NAME, hook->ops.dev->name)) - goto nla_put_failure; + if (hook_list) { + list_for_each_entry_rcu(hook, hook_list, list) { + if (nla_put_string(skb, NFTA_DEVICE_NAME, hook->ops.dev->name)) + goto nla_put_failure; + } + } else if (trans_hook_list) { + list_for_each_entry(trans_hook, trans_hook_list, list) { + if (nla_put_string(skb, NFTA_DEVICE_NAME, + trans_hook->hook->ops.dev->name)) + goto nla_put_failure; + } + } nla_nest_end(skb, nest_devs); nla_nest_end(skb, nest); @@ -9004,7 +9146,7 @@ static int nf_tables_dump_flowtable(struct sk_buff *skb, NFT_MSG_NEWFLOWTABLE, NLM_F_MULTI | NLM_F_APPEND, table->family, - flowtable, NULL) < 0) + flowtable, NULL, NULL) < 0) goto done; nl_dump_check_consistent(cb, nlmsg_hdr(skb)); @@ -9099,7 +9241,7 @@ static int nf_tables_getflowtable(struct sk_buff *skb, err = nf_tables_fill_flowtable_info(skb2, net, NETLINK_CB(skb).portid, info->nlh->nlmsg_seq, NFT_MSG_NEWFLOWTABLE, 0, family, - flowtable, NULL); + flowtable, NULL, NULL); if (err < 0) goto err_fill_flowtable_info; @@ -9112,7 +9254,9 @@ static int nf_tables_getflowtable(struct sk_buff *skb, static void nf_tables_flowtable_notify(struct nft_ctx *ctx, struct nft_flowtable *flowtable, - struct list_head *hook_list, int event) + struct list_head *hook_list, + struct list_head *trans_hook_list, + int event) { struct nftables_pernet *nft_net = nft_pernet(ctx->net); struct sk_buff *skb; @@ -9132,7 +9276,8 @@ static void nf_tables_flowtable_notify(struct nft_ctx *ctx, err = nf_tables_fill_flowtable_info(skb, ctx->net, ctx->portid, ctx->seq, event, flags, - ctx->family, flowtable, hook_list); + ctx->family, flowtable, + hook_list, trans_hook_list); if (err < 0) { kfree_skb(skb); goto err; @@ -9573,9 +9718,7 @@ static void nft_commit_release(struct nft_trans *trans) break; case NFT_MSG_DELCHAIN: case NFT_MSG_DESTROYCHAIN: - if (nft_trans_chain_update(trans)) - nft_hooks_destroy(&nft_trans_chain_hooks(trans)); - else + if (!nft_trans_chain_update(trans)) nf_tables_chain_destroy(nft_trans_chain(trans)); break; case NFT_MSG_DELRULE: @@ -9598,9 +9741,7 @@ static void nft_commit_release(struct nft_trans *trans) break; case NFT_MSG_DELFLOWTABLE: case NFT_MSG_DESTROYFLOWTABLE: - if (nft_trans_flowtable_update(trans)) - nft_hooks_destroy(&nft_trans_flowtable_hooks(trans)); - else + if (!nft_trans_flowtable_update(trans)) nf_tables_flowtable_destroy(nft_trans_flowtable(trans)); break; } @@ -10349,31 +10490,28 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) if (nft_trans_chain_update(trans)) { nft_chain_commit_update(trans); nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN, - &nft_trans_chain_hooks(trans)); + &nft_trans_chain_hooks(trans), NULL); list_splice_rcu(&nft_trans_chain_hooks(trans), &nft_trans_basechain(trans)->hook_list); /* trans destroyed after rcu grace period */ } else { nft_chain_commit_drop_policy(trans); nft_clear(net, trans->ctx.chain); - nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN, NULL); + nf_tables_chain_notify(&trans->ctx, NFT_MSG_NEWCHAIN, NULL, NULL); nft_trans_destroy(trans); } break; case NFT_MSG_DELCHAIN: case NFT_MSG_DESTROYCHAIN: if (nft_trans_chain_update(trans)) { - nf_tables_chain_notify(&trans->ctx, NFT_MSG_DELCHAIN, + nf_tables_chain_notify(&trans->ctx, NFT_MSG_DELCHAIN, NULL, &nft_trans_chain_hooks(trans)); - if (!(trans->ctx.table->flags & NFT_TABLE_F_DORMANT)) { - nft_netdev_unregister_hooks(net, - &nft_trans_chain_hooks(trans), - true); - } + nft_netdev_unregister_trans_hook(net, trans->ctx.table, + &nft_trans_chain_hooks(trans)); } else { nft_chain_del(trans->ctx.chain); nf_tables_chain_notify(&trans->ctx, NFT_MSG_DELCHAIN, - NULL); + NULL, NULL); nf_tables_unregister_hook(trans->ctx.net, trans->ctx.table, trans->ctx.chain); @@ -10490,6 +10628,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) nf_tables_flowtable_notify(&trans->ctx, nft_trans_flowtable(trans), &nft_trans_flowtable_hooks(trans), + NULL, NFT_MSG_NEWFLOWTABLE); list_splice_rcu(&nft_trans_flowtable_hooks(trans), &nft_trans_flowtable(trans)->hook_list); @@ -10498,6 +10637,7 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) nf_tables_flowtable_notify(&trans->ctx, nft_trans_flowtable(trans), NULL, + NULL, NFT_MSG_NEWFLOWTABLE); } nft_trans_destroy(trans); @@ -10507,16 +10647,18 @@ static int nf_tables_commit(struct net *net, struct sk_buff *skb) if (nft_trans_flowtable_update(trans)) { nf_tables_flowtable_notify(&trans->ctx, nft_trans_flowtable(trans), + NULL, &nft_trans_flowtable_hooks(trans), trans->msg_type); - nft_unregister_flowtable_net_hooks(net, - nft_trans_flowtable(trans), - &nft_trans_flowtable_hooks(trans)); + nft_flowtable_unregister_trans_hook(net, + nft_trans_flowtable(trans), + &nft_trans_flowtable_hooks(trans)); } else { list_del_rcu(&nft_trans_flowtable(trans)->list); nf_tables_flowtable_notify(&trans->ctx, nft_trans_flowtable(trans), NULL, + NULL, trans->msg_type); nft_unregister_flowtable_net_hooks(net, nft_trans_flowtable(trans), @@ -10667,8 +10809,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) case NFT_MSG_DELCHAIN: case NFT_MSG_DESTROYCHAIN: if (nft_trans_chain_update(trans)) { - list_splice(&nft_trans_chain_hooks(trans), - &nft_trans_basechain(trans)->hook_list); + nft_trans_delhook_abort(&nft_trans_chain_hooks(trans)); } else { nft_use_inc_restore(&trans->ctx.table->use); nft_clear(trans->ctx.net, trans->ctx.chain); @@ -10785,8 +10926,7 @@ static int __nf_tables_abort(struct net *net, enum nfnl_abort_action action) case NFT_MSG_DELFLOWTABLE: case NFT_MSG_DESTROYFLOWTABLE: if (nft_trans_flowtable_update(trans)) { - list_splice(&nft_trans_flowtable_hooks(trans), - &nft_trans_flowtable(trans)->hook_list); + nft_trans_delhook_abort(&nft_trans_flowtable_hooks(trans)); } else { nft_use_inc_restore(&trans->ctx.table->use); nft_clear(trans->ctx.net, nft_trans_flowtable(trans)); -- 2.25.1