[PATCH AUTOSEL 5.0 061/173] netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression

[PATCH AUTOSEL 5.0 061/173] netfilter: ctnetlink: Resolve conntrack L3-protocol flush regression

[Sasha Levin]

From: Kristian Evensen <kristian.evensen@gmail.com>

[ Upstream commit f8e608982022fad035160870f5b06086d3cba54d ]

Commit 59c08c69c278 ("netfilter: ctnetlink: Support L3 protocol-filter
on flush") introduced a user-space regression when flushing connection
track entries. Before this commit, the nfgen_family field was not used
by the kernel and all entries were removed. Since this commit,
nfgen_family is used to filter out entries that should not be removed.
One example a broken tool is conntrack. conntrack always sets
nfgen_family to AF_INET, so after 59c08c69c278 only IPv4 entries were
removed with the -F parameter.

Pablo Neira Ayuso suggested using nfgenmsg->version to resolve the
regression, and this commit implements his suggestion. nfgenmsg->version
is so far set to zero, so it is well-suited to be used as a flag for
selecting old or new flush behavior. If version is 0, nfgen_family is
ignored and all entries are used. If user-space sets the version to one
(or any other value than 0), then the new behavior is used. As version
only can have two valid values, I chose not to add a new
NFNETLINK_VERSION-constant.

Fixes: 59c08c69c278 ("netfilter: ctnetlink: Support L3 protocol-filter on flush")
Reported-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Kristian Evensen <kristian.evensen@gmail.com>
Tested-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_conntrack_netlink.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_netlink.c b/net/netfilter/nf_conntrack_netlink.c
index 36619ad8ab8c2..8233dfafb339d 100644
--- a/net/netfilter/nf_conntrack_netlink.c
+++ b/net/netfilter/nf_conntrack_netlink.c
@@ -1254,7 +1254,7 @@ static int ctnetlink_del_conntrack(struct net *net, struct sock *ctnl,
 	struct nf_conntrack_tuple tuple;
 	struct nf_conn *ct;
 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
-	u_int8_t u3 = nfmsg->nfgen_family;
+	u_int8_t u3 = nfmsg->version ? nfmsg->nfgen_family : AF_UNSPEC;
 	struct nf_conntrack_zone zone;
 	int err;
 
-- 
2.20.1

[PATCH AUTOSEL 5.0 064/173] netfilter: nf_flow_table: fix missing error check for rhashtable_insert_fast

[Sasha Levin]

From: Taehee Yoo <ap420073@gmail.com>

[ Upstream commit 43c8f131184faf20c07221f3e09724611c6525d8 ]

rhashtable_insert_fast() may return an error value when memory
allocation fails, but flow_offload_add() does not check for errors.
This patch just adds missing error checking.

Fixes: ac2a66665e23 ("netfilter: add generic flow table infrastructure")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_flow_table_core.c | 25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/net/netfilter/nf_flow_table_core.c b/net/netfilter/nf_flow_table_core.c
index c0c72ae9df42f..604446c0264cc 100644
--- a/net/netfilter/nf_flow_table_core.c
+++ b/net/netfilter/nf_flow_table_core.c
@@ -185,14 +185,25 @@ static const struct rhashtable_params nf_flow_offload_rhash_params = {
 
 int flow_offload_add(struct nf_flowtable *flow_table, struct flow_offload *flow)
 {
-	flow->timeout = (u32)jiffies;
+	int err;
 
-	rhashtable_insert_fast(&flow_table->rhashtable,
-			       &flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].node,
-			       nf_flow_offload_rhash_params);
-	rhashtable_insert_fast(&flow_table->rhashtable,
-			       &flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].node,
-			       nf_flow_offload_rhash_params);
+	err = rhashtable_insert_fast(&flow_table->rhashtable,
+				     &flow->tuplehash[0].node,
+				     nf_flow_offload_rhash_params);
+	if (err < 0)
+		return err;
+
+	err = rhashtable_insert_fast(&flow_table->rhashtable,
+				     &flow->tuplehash[1].node,
+				     nf_flow_offload_rhash_params);
+	if (err < 0) {
+		rhashtable_remove_fast(&flow_table->rhashtable,
+				       &flow->tuplehash[0].node,
+				       nf_flow_offload_rhash_params);
+		return err;
+	}
+
+	flow->timeout = (u32)jiffies;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(flow_offload_add);
-- 
2.20.1

[PATCH AUTOSEL 5.0 065/173] netfilter: nf_conntrack_h323: restore boundary check correctness

[Sasha Levin]

From: Jakub Jankowski <shasta@toxcorp.com>

[ Upstream commit f5e85ce8e733c2547827f6268136b70b802eabdb ]

Since commit bc7d811ace4a ("netfilter: nf_ct_h323: Convert
CHECK_BOUND macro to function"), NAT traversal for H.323
doesn't work, failing to parse H323-UserInformation.
nf_h323_error_boundary() compares contents of the bitstring,
not the addresses, preventing valid H.323 packets from being
conntrack'd.

This looks like an oversight from when CHECK_BOUND macro was
converted to a function.

To fix it, stop dereferencing bs->cur and bs->end.

Fixes: bc7d811ace4a ("netfilter: nf_ct_h323: Convert CHECK_BOUND macro to function")
Signed-off-by: Jakub Jankowski <shasta@toxcorp.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_conntrack_h323_asn1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c
index 1601275efe2d1..4c2ef42e189cb 100644
--- a/net/netfilter/nf_conntrack_h323_asn1.c
+++ b/net/netfilter/nf_conntrack_h323_asn1.c
@@ -172,7 +172,7 @@ static int nf_h323_error_boundary(struct bitstr *bs, size_t bytes, size_t bits)
 	if (bits % BITS_PER_BYTE > 0)
 		bytes++;
 
-	if (*bs->cur + bytes > *bs->end)
+	if (bs->cur + bytes > bs->end)
 		return 1;
 
 	return 0;
-- 
2.20.1

[PATCH AUTOSEL 5.0 067/173] netfilter: nf_tables: fix base chain stat rcu_dereference usage

[Sasha Levin]

From: Florian Westphal <fw@strlen.de>

[ Upstream commit edbd82c5fba009f68d20b5db585be1e667c605f6 ]

Following splat gets triggered when nfnetlink monitor is running while
xtables-nft selftests are running:

net/netfilter/nf_tables_api.c:1272 suspicious rcu_dereference_check() usage!
other info that might help us debug this:

1 lock held by xtables-nft-mul/27006:
 #0: 00000000e0f85be9 (&net->nft.commit_mutex){+.+.}, at: nf_tables_valid_genid+0x1a/0x50
Call Trace:
 nf_tables_fill_chain_info.isra.45+0x6cc/0x6e0
 nf_tables_chain_notify+0xf8/0x1a0
 nf_tables_commit+0x165c/0x1740

nf_tables_fill_chain_info() can be called both from dumps (rcu read locked)
or from the transaction path if a userspace process subscribed to nftables
notifications.

In the 'table dump' case, rcu_access_pointer() cannot be used: We do not
hold transaction mutex so the pointer can be NULLed right after the check.
Just unconditionally fetch the value, then have the helper return
immediately if its NULL.

In the notification case we don't hold the rcu read lock, but updates are
prevented due to transaction mutex. Use rcu_dereference_check() to make lockdep
aware of this.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/netfilter/nf_tables_api.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 25c2b98b9a960..eb3915b76ff47 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -1147,6 +1147,9 @@ static int nft_dump_stats(struct sk_buff *skb, struct nft_stats __percpu *stats)
 	u64 pkts, bytes;
 	int cpu;
 
+	if (!stats)
+		return 0;
+
 	memset(&total, 0, sizeof(total));
 	for_each_possible_cpu(cpu) {
 		cpu_stats = per_cpu_ptr(stats, cpu);
@@ -1204,6 +1207,7 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net,
 	if (nft_is_base_chain(chain)) {
 		const struct nft_base_chain *basechain = nft_base_chain(chain);
 		const struct nf_hook_ops *ops = &basechain->ops;
+		struct nft_stats __percpu *stats;
 		struct nlattr *nest;
 
 		nest = nla_nest_start(skb, NFTA_CHAIN_HOOK);
@@ -1225,8 +1229,9 @@ static int nf_tables_fill_chain_info(struct sk_buff *skb, struct net *net,
 		if (nla_put_string(skb, NFTA_CHAIN_TYPE, basechain->type->name))
 			goto nla_put_failure;
 
-		if (rcu_access_pointer(basechain->stats) &&
-		    nft_dump_stats(skb, rcu_dereference(basechain->stats)))
+		stats = rcu_dereference_check(basechain->stats,
+					      lockdep_commit_lock_is_held(net));
+		if (nft_dump_stats(skb, stats))
 			goto nla_put_failure;
 	}
 
-- 
2.20.1