[PATCH 4.19 1/3] netfilter: nf_tables: incorrect error path handling with NFT_MSG_NEWRULE
From: Pablo Neira Ayuso pablo@netfilter.org
mainline inclusion from mainline-v6.4-rc7 commit 1240eb93f0616b21c675416516ff3d74798fdc97 category: bugfix bugzilla: 188953 CVE: CVE-2023-3117
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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In case of error when adding a new rule that refers to an anonymous set, deactivate expressions via NFT_TRANS_PREPARE state, not NFT_TRANS_RELEASE. Thus, the lookup expression marks anonymous sets as inactive in the next generation to ensure it is not reachable in this transaction anymore and decrement the set refcount as introduced by c1592a89942e ("netfilter: nf_tables: deactivate anonymous set from preparation phase"). The abort step takes care of undoing the anonymous set.
This is also consistent with rule deletion, where NFT_TRANS_PREPARE is used. Note that this error path is exercised in the preparation step of the commit protocol. This patch replaces nf_tables_rule_release() by the deactivate and destroy calls, this time with NFT_TRANS_PREPARE.
Due to this incorrect error handling, it is possible to access a dangling pointer to the anonymous set that remains in the transaction list.
[1009.379054] BUG: KASAN: use-after-free in nft_set_lookup_global+0x147/0x1a0 [nf_tables] [1009.379106] Read of size 8 at addr ffff88816c4c8020 by task nft-rule-add/137110 [1009.379116] CPU: 7 PID: 137110 Comm: nft-rule-add Not tainted 6.4.0-rc4+ #256 [1009.379128] Call Trace: [1009.379132] <TASK> [1009.379135] dump_stack_lvl+0x33/0x50 [1009.379146] ? nft_set_lookup_global+0x147/0x1a0 [nf_tables] [1009.379191] print_address_description.constprop.0+0x27/0x300 [1009.379201] kasan_report+0x107/0x120 [1009.379210] ? nft_set_lookup_global+0x147/0x1a0 [nf_tables] [1009.379255] nft_set_lookup_global+0x147/0x1a0 [nf_tables] [1009.379302] nft_lookup_init+0xa5/0x270 [nf_tables] [1009.379350] nf_tables_newrule+0x698/0xe50 [nf_tables] [1009.379397] ? nf_tables_rule_release+0xe0/0xe0 [nf_tables] [1009.379441] ? kasan_unpoison+0x23/0x50 [1009.379450] nfnetlink_rcv_batch+0x97c/0xd90 [nfnetlink] [1009.379470] ? nfnetlink_rcv_msg+0x480/0x480 [nfnetlink] [1009.379485] ? __alloc_skb+0xb8/0x1e0 [1009.379493] ? __alloc_skb+0xb8/0x1e0 [1009.379502] ? entry_SYSCALL_64_after_hwframe+0x46/0xb0 [1009.379509] ? unwind_get_return_address+0x2a/0x40 [1009.379517] ? write_profile+0xc0/0xc0 [1009.379524] ? avc_lookup+0x8f/0xc0 [1009.379532] ? __rcu_read_unlock+0x43/0x60
Fixes: 958bee14d071 ("netfilter: nf_tables: use new transaction infrastructure to handle sets") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org
conflict: net/netfilter/nf_tables_api.c
Signed-off-by: Lu Wei luwei32@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Reviewed-by: Wang Weiyang wangweiyang2@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- net/netfilter/nf_tables_api.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index f76558e03b24..0e27e489fc69 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2755,7 +2755,8 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
return 0; err2: - nf_tables_rule_release(&ctx, rule); + nft_rule_expr_deactivate(&ctx, rule, NFT_TRANS_PREPARE); + nf_tables_rule_destroy(&ctx, rule); err1: for (i = 0; i < n; i++) { if (info[i].ops) {
From: Pablo Neira Ayuso pablo@netfilter.org
mainline inclusion from mainline-v6.4 commit 26b5a5712eb85e253724e56a54c17f8519bd8e4e category: bugfix bugzilla: 188953 CVE: CVE-2023-3117
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Add a new state to deal with rule expressions deactivation from the newrule error path, otherwise the anonymous set remains in the list in inactive state for the next generation. Mark the set/chain transaction as unbound so the abort path releases this object, set it as inactive in the next generation so it is not reachable anymore from this transaction and reference counter is dropped.
Fixes: 1240eb93f061 ("netfilter: nf_tables: incorrect error path handling with NFT_MSG_NEWRULE") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org
conflict: include/net/netfilter/nf_tables.h net/netfilter/nf_tables_api.c
Signed-off-by: Lu Wei luwei32@huawei.com Reviewed-by: Yue Haibing yuehaibing@huawei.com Reviewed-by: Wang Weiyang wangweiyang2@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- include/net/netfilter/nf_tables.h | 1 + net/netfilter/nf_tables_api.c | 26 ++++++++++++++++++++++---- 2 files changed, 23 insertions(+), 4 deletions(-)
diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 78f5f0426e6b..ecc301ee1556 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -733,6 +733,7 @@ struct nft_expr_type {
enum nft_trans_phase { NFT_TRANS_PREPARE, + NFT_TRANS_PREPARE_ERROR, NFT_TRANS_ABORT, NFT_TRANS_COMMIT, NFT_TRANS_RELEASE diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 0e27e489fc69..3d642e9edebc 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -115,7 +115,8 @@ static void nft_trans_destroy(struct nft_trans *trans) kfree(trans); }
-static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set) +static void __nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set, + bool bind) { struct net *net = ctx->net; struct nft_trans *trans; @@ -127,16 +128,26 @@ static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set) switch (trans->msg_type) { case NFT_MSG_NEWSET: if (nft_trans_set(trans) == set) - nft_trans_set_bound(trans) = true; + nft_trans_set_bound(trans) = bind; break; case NFT_MSG_NEWSETELEM: if (nft_trans_elem_set(trans) == set) - nft_trans_elem_set_bound(trans) = true; + nft_trans_elem_set_bound(trans) = bind; break; } } }
+static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set) +{ + return __nft_set_trans_bind(ctx, set, true); +} + +static void nft_set_trans_unbind(const struct nft_ctx *ctx, struct nft_set *set) +{ + return __nft_set_trans_bind(ctx, set, false); +} + static int nf_tables_register_hook(struct net *net, const struct nft_table *table, struct nft_chain *chain) @@ -2755,7 +2766,7 @@ static int nf_tables_newrule(struct net *net, struct sock *nlsk,
return 0; err2: - nft_rule_expr_deactivate(&ctx, rule, NFT_TRANS_PREPARE); + nft_rule_expr_deactivate(&ctx, rule, NFT_TRANS_PREPARE_ERROR); nf_tables_rule_destroy(&ctx, rule); err1: for (i = 0; i < n; i++) { @@ -3775,6 +3786,13 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set, enum nft_trans_phase phase) { switch (phase) { + case NFT_TRANS_PREPARE_ERROR: + nft_set_trans_unbind(ctx, set); + if (nft_set_is_anonymous(set)) + nft_deactivate_next(ctx->net, set); + + set->use--; + break; case NFT_TRANS_PREPARE: if (nft_set_is_anonymous(set)) nft_deactivate_next(ctx->net, set);
From: Pablo Neira Ayuso pablo@netfilter.org
mainline inclusion from mainline-v6.4 commit 3e70489721b6c870252c9082c496703677240f53 category: bugfix bugzilla: 188953 CVE: CVE-2023-3117
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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Otherwise a dangling reference to a rule object that is gone remains in the set binding list.
Fixes: 26b5a5712eb8 ("netfilter: nf_tables: add NFT_TRANS_PREPARE_ERROR to deal with bound set/chain") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Reviewed-by: Yue Haibing yuehaibing@huawei.com Reviewed-by: Wang Weiyang wangweiyang2@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- net/netfilter/nf_tables_api.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 3d642e9edebc..c3fedbfd0ee2 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -3790,6 +3790,8 @@ void nf_tables_deactivate_set(const struct nft_ctx *ctx, struct nft_set *set, nft_set_trans_unbind(ctx, set); if (nft_set_is_anonymous(set)) nft_deactivate_next(ctx->net, set); + else + list_del_rcu(&binding->list);
set->use--; break;
-
Yongqiang Liu