* [PATCH net 1/3] netfilter: nf_tables: initialize set before expression setup
2021-06-10 16:54 [PATCH net 0/3] Netfilter fixes for net Pablo Neira Ayuso
@ 2021-06-10 16:54 ` Pablo Neira Ayuso
2021-06-10 21:50 ` patchwork-bot+netdevbpf
2021-06-10 16:54 ` [PATCH net 2/3] selftests: netfilter: add fib test case Pablo Neira Ayuso
2021-06-10 16:54 ` [PATCH net 3/3] netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local Pablo Neira Ayuso
2 siblings, 1 reply; 5+ messages in thread
From: Pablo Neira Ayuso @ 2021-06-10 16:54 UTC (permalink / raw)
To: netfilter-devel; +Cc: davem, netdev, kuba
nft_set_elem_expr_alloc() needs an initialized set if expression sets on
the NFT_EXPR_GC flag. Move set fields initialization before expression
setup.
[4512935.019450] ==================================================================
[4512935.019456] BUG: KASAN: null-ptr-deref in nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019487] Read of size 8 at addr 0000000000000070 by task nft/23532
[4512935.019494] CPU: 1 PID: 23532 Comm: nft Not tainted 5.12.0-rc4+ #48
[...]
[4512935.019502] Call Trace:
[4512935.019505] dump_stack+0x89/0xb4
[4512935.019512] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019536] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019560] kasan_report.cold.12+0x5f/0xd8
[4512935.019566] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019590] nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
[4512935.019615] nf_tables_newset+0xc7f/0x1460 [nf_tables]
Reported-by: syzbot+ce96ca2b1d0b37c6422d@syzkaller.appspotmail.com
Fixes: 65038428b2c6 ("netfilter: nf_tables: allow to specify stateful expression in set definition")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/netfilter/nf_tables_api.c | 85 ++++++++++++++++++-----------------
1 file changed, 43 insertions(+), 42 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 72bc759179ef..bf4d6ec9fc55 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -4364,13 +4364,45 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
err = nf_tables_set_alloc_name(&ctx, set, name);
kfree(name);
if (err < 0)
- goto err_set_alloc_name;
+ goto err_set_name;
+
+ udata = NULL;
+ if (udlen) {
+ udata = set->data + size;
+ nla_memcpy(udata, nla[NFTA_SET_USERDATA], udlen);
+ }
+
+ INIT_LIST_HEAD(&set->bindings);
+ INIT_LIST_HEAD(&set->catchall_list);
+ set->table = table;
+ write_pnet(&set->net, net);
+ set->ops = ops;
+ set->ktype = ktype;
+ set->klen = desc.klen;
+ set->dtype = dtype;
+ set->objtype = objtype;
+ set->dlen = desc.dlen;
+ set->flags = flags;
+ set->size = desc.size;
+ set->policy = policy;
+ set->udlen = udlen;
+ set->udata = udata;
+ set->timeout = timeout;
+ set->gc_int = gc_int;
+
+ set->field_count = desc.field_count;
+ for (i = 0; i < desc.field_count; i++)
+ set->field_len[i] = desc.field_len[i];
+
+ err = ops->init(set, &desc, nla);
+ if (err < 0)
+ goto err_set_init;
if (nla[NFTA_SET_EXPR]) {
expr = nft_set_elem_expr_alloc(&ctx, set, nla[NFTA_SET_EXPR]);
if (IS_ERR(expr)) {
err = PTR_ERR(expr);
- goto err_set_alloc_name;
+ goto err_set_expr_alloc;
}
set->exprs[0] = expr;
set->num_exprs++;
@@ -4381,75 +4413,44 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info,
if (!(flags & NFT_SET_EXPR)) {
err = -EINVAL;
- goto err_set_alloc_name;
+ goto err_set_expr_alloc;
}
i = 0;
nla_for_each_nested(tmp, nla[NFTA_SET_EXPRESSIONS], left) {
if (i == NFT_SET_EXPR_MAX) {
err = -E2BIG;
- goto err_set_init;
+ goto err_set_expr_alloc;
}
if (nla_type(tmp) != NFTA_LIST_ELEM) {
err = -EINVAL;
- goto err_set_init;
+ goto err_set_expr_alloc;
}
expr = nft_set_elem_expr_alloc(&ctx, set, tmp);
if (IS_ERR(expr)) {
err = PTR_ERR(expr);
- goto err_set_init;
+ goto err_set_expr_alloc;
}
set->exprs[i++] = expr;
set->num_exprs++;
}
}
- udata = NULL;
- if (udlen) {
- udata = set->data + size;
- nla_memcpy(udata, nla[NFTA_SET_USERDATA], udlen);
- }
-
- INIT_LIST_HEAD(&set->bindings);
- INIT_LIST_HEAD(&set->catchall_list);
- set->table = table;
- write_pnet(&set->net, net);
- set->ops = ops;
- set->ktype = ktype;
- set->klen = desc.klen;
- set->dtype = dtype;
- set->objtype = objtype;
- set->dlen = desc.dlen;
- set->flags = flags;
- set->size = desc.size;
- set->policy = policy;
- set->udlen = udlen;
- set->udata = udata;
- set->timeout = timeout;
- set->gc_int = gc_int;
set->handle = nf_tables_alloc_handle(table);
- set->field_count = desc.field_count;
- for (i = 0; i < desc.field_count; i++)
- set->field_len[i] = desc.field_len[i];
-
- err = ops->init(set, &desc, nla);
- if (err < 0)
- goto err_set_init;
-
err = nft_trans_set_add(&ctx, NFT_MSG_NEWSET, set);
if (err < 0)
- goto err_set_trans;
+ goto err_set_expr_alloc;
list_add_tail_rcu(&set->list, &table->sets);
table->use++;
return 0;
-err_set_trans:
- ops->destroy(set);
-err_set_init:
+err_set_expr_alloc:
for (i = 0; i < set->num_exprs; i++)
nft_expr_destroy(&ctx, set->exprs[i]);
-err_set_alloc_name:
+
+ ops->destroy(set);
+err_set_init:
kfree(set->name);
err_set_name:
kvfree(set);
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH net 1/3] netfilter: nf_tables: initialize set before expression setup
2021-06-10 16:54 ` [PATCH net 1/3] netfilter: nf_tables: initialize set before expression setup Pablo Neira Ayuso
@ 2021-06-10 21:50 ` patchwork-bot+netdevbpf
0 siblings, 0 replies; 5+ messages in thread
From: patchwork-bot+netdevbpf @ 2021-06-10 21:50 UTC (permalink / raw)
To: Pablo Neira Ayuso; +Cc: netfilter-devel, davem, netdev, kuba
Hello:
This series was applied to netdev/net.git (refs/heads/master):
On Thu, 10 Jun 2021 18:54:56 +0200 you wrote:
> nft_set_elem_expr_alloc() needs an initialized set if expression sets on
> the NFT_EXPR_GC flag. Move set fields initialization before expression
> setup.
>
> [4512935.019450] ==================================================================
> [4512935.019456] BUG: KASAN: null-ptr-deref in nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
> [4512935.019487] Read of size 8 at addr 0000000000000070 by task nft/23532
> [4512935.019494] CPU: 1 PID: 23532 Comm: nft Not tainted 5.12.0-rc4+ #48
> [...]
> [4512935.019502] Call Trace:
> [4512935.019505] dump_stack+0x89/0xb4
> [4512935.019512] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
> [4512935.019536] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
> [4512935.019560] kasan_report.cold.12+0x5f/0xd8
> [4512935.019566] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
> [4512935.019590] nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables]
> [4512935.019615] nf_tables_newset+0xc7f/0x1460 [nf_tables]
>
> [...]
Here is the summary with links:
- [net,1/3] netfilter: nf_tables: initialize set before expression setup
https://git.kernel.org/netdev/net/c/ad9f151e560b
- [net,2/3] selftests: netfilter: add fib test case
https://git.kernel.org/netdev/net/c/82944421243e
- [net,3/3] netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local
https://git.kernel.org/netdev/net/c/12f36e9bf678
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCH net 2/3] selftests: netfilter: add fib test case
2021-06-10 16:54 [PATCH net 0/3] Netfilter fixes for net Pablo Neira Ayuso
2021-06-10 16:54 ` [PATCH net 1/3] netfilter: nf_tables: initialize set before expression setup Pablo Neira Ayuso
@ 2021-06-10 16:54 ` Pablo Neira Ayuso
2021-06-10 16:54 ` [PATCH net 3/3] netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local Pablo Neira Ayuso
2 siblings, 0 replies; 5+ messages in thread
From: Pablo Neira Ayuso @ 2021-06-10 16:54 UTC (permalink / raw)
To: netfilter-devel; +Cc: davem, netdev, kuba
From: Florian Westphal <fw@strlen.de>
There is a bug report on netfilter.org bugzilla pointing to fib
expression dropping ipv6 DAD packets.
Add a test case that demonstrates this problem.
Next patch excludes icmpv6 packets coming from any to linklocal.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
tools/testing/selftests/netfilter/Makefile | 2 +-
tools/testing/selftests/netfilter/nft_fib.sh | 221 +++++++++++++++++++
2 files changed, 222 insertions(+), 1 deletion(-)
create mode 100755 tools/testing/selftests/netfilter/nft_fib.sh
diff --git a/tools/testing/selftests/netfilter/Makefile b/tools/testing/selftests/netfilter/Makefile
index 3171069a6b46..cd6430b39982 100644
--- a/tools/testing/selftests/netfilter/Makefile
+++ b/tools/testing/selftests/netfilter/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for netfilter selftests
-TEST_PROGS := nft_trans_stress.sh nft_nat.sh bridge_brouter.sh \
+TEST_PROGS := nft_trans_stress.sh nft_fib.sh nft_nat.sh bridge_brouter.sh \
conntrack_icmp_related.sh nft_flowtable.sh ipvs.sh \
nft_concat_range.sh nft_conntrack_helper.sh \
nft_queue.sh nft_meta.sh nf_nat_edemux.sh \
diff --git a/tools/testing/selftests/netfilter/nft_fib.sh b/tools/testing/selftests/netfilter/nft_fib.sh
new file mode 100755
index 000000000000..6caf6ac8c285
--- /dev/null
+++ b/tools/testing/selftests/netfilter/nft_fib.sh
@@ -0,0 +1,221 @@
+#!/bin/bash
+#
+# This tests the fib expression.
+#
+# Kselftest framework requirement - SKIP code is 4.
+ksft_skip=4
+ret=0
+
+sfx=$(mktemp -u "XXXXXXXX")
+ns1="ns1-$sfx"
+ns2="ns2-$sfx"
+nsrouter="nsrouter-$sfx"
+timeout=4
+
+log_netns=$(sysctl -n net.netfilter.nf_log_all_netns)
+
+cleanup()
+{
+ ip netns del ${ns1}
+ ip netns del ${ns2}
+ ip netns del ${nsrouter}
+
+ [ $log_netns -eq 0 ] && sysctl -q net.netfilter.nf_log_all_netns=$log_netns
+}
+
+nft --version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+ echo "SKIP: Could not run test without nft tool"
+ exit $ksft_skip
+fi
+
+ip -Version > /dev/null 2>&1
+if [ $? -ne 0 ];then
+ echo "SKIP: Could not run test without ip tool"
+ exit $ksft_skip
+fi
+
+ip netns add ${nsrouter}
+if [ $? -ne 0 ];then
+ echo "SKIP: Could not create net namespace"
+ exit $ksft_skip
+fi
+
+trap cleanup EXIT
+
+dmesg | grep -q ' nft_rpfilter: '
+if [ $? -eq 0 ]; then
+ dmesg -c | grep ' nft_rpfilter: '
+ echo "WARN: a previous test run has failed" 1>&2
+fi
+
+sysctl -q net.netfilter.nf_log_all_netns=1
+ip netns add ${ns1}
+ip netns add ${ns2}
+
+load_ruleset() {
+ local netns=$1
+
+ip netns exec ${netns} nft -f /dev/stdin <<EOF
+table inet filter {
+ chain prerouting {
+ type filter hook prerouting priority 0; policy accept;
+ fib saddr . iif oif missing counter log prefix "$netns nft_rpfilter: " drop
+ }
+}
+EOF
+}
+
+load_ruleset_count() {
+ local netns=$1
+
+ip netns exec ${netns} nft -f /dev/stdin <<EOF
+table inet filter {
+ chain prerouting {
+ type filter hook prerouting priority 0; policy accept;
+ ip daddr 1.1.1.1 fib saddr . iif oif missing counter drop
+ ip6 daddr 1c3::c01d fib saddr . iif oif missing counter drop
+ }
+}
+EOF
+}
+
+check_drops() {
+ dmesg | grep -q ' nft_rpfilter: '
+ if [ $? -eq 0 ]; then
+ dmesg | grep ' nft_rpfilter: '
+ echo "FAIL: rpfilter did drop packets"
+ return 1
+ fi
+
+ return 0
+}
+
+check_fib_counter() {
+ local want=$1
+ local ns=$2
+ local address=$3
+
+ line=$(ip netns exec ${ns} nft list table inet filter | grep 'fib saddr . iif' | grep $address | grep "packets $want" )
+ ret=$?
+
+ if [ $ret -ne 0 ];then
+ echo "Netns $ns fib counter doesn't match expected packet count of $want for $address" 1>&2
+ ip netns exec ${ns} nft list table inet filter
+ return 1
+ fi
+
+ if [ $want -gt 0 ]; then
+ echo "PASS: fib expression did drop packets for $address"
+ fi
+
+ return 0
+}
+
+load_ruleset ${nsrouter}
+load_ruleset ${ns1}
+load_ruleset ${ns2}
+
+ip link add veth0 netns ${nsrouter} type veth peer name eth0 netns ${ns1} > /dev/null 2>&1
+if [ $? -ne 0 ];then
+ echo "SKIP: No virtual ethernet pair device support in kernel"
+ exit $ksft_skip
+fi
+ip link add veth1 netns ${nsrouter} type veth peer name eth0 netns ${ns2}
+
+ip -net ${nsrouter} link set lo up
+ip -net ${nsrouter} link set veth0 up
+ip -net ${nsrouter} addr add 10.0.1.1/24 dev veth0
+ip -net ${nsrouter} addr add dead:1::1/64 dev veth0
+
+ip -net ${nsrouter} link set veth1 up
+ip -net ${nsrouter} addr add 10.0.2.1/24 dev veth1
+ip -net ${nsrouter} addr add dead:2::1/64 dev veth1
+
+ip -net ${ns1} link set lo up
+ip -net ${ns1} link set eth0 up
+
+ip -net ${ns2} link set lo up
+ip -net ${ns2} link set eth0 up
+
+ip -net ${ns1} addr add 10.0.1.99/24 dev eth0
+ip -net ${ns1} addr add dead:1::99/64 dev eth0
+ip -net ${ns1} route add default via 10.0.1.1
+ip -net ${ns1} route add default via dead:1::1
+
+ip -net ${ns2} addr add 10.0.2.99/24 dev eth0
+ip -net ${ns2} addr add dead:2::99/64 dev eth0
+ip -net ${ns2} route add default via 10.0.2.1
+ip -net ${ns2} route add default via dead:2::1
+
+test_ping() {
+ local daddr4=$1
+ local daddr6=$2
+
+ ip netns exec ${ns1} ping -c 1 -q $daddr4 > /dev/null
+ ret=$?
+ if [ $ret -ne 0 ];then
+ check_drops
+ echo "FAIL: ${ns1} cannot reach $daddr4, ret $ret" 1>&2
+ return 1
+ fi
+
+ ip netns exec ${ns1} ping -c 3 -q $daddr6 > /dev/null
+ ret=$?
+ if [ $ret -ne 0 ];then
+ check_drops
+ echo "FAIL: ${ns1} cannot reach $daddr6, ret $ret" 1>&2
+ return 1
+ fi
+
+ return 0
+}
+
+ip netns exec ${nsrouter} sysctl net.ipv6.conf.all.forwarding=1 > /dev/null
+ip netns exec ${nsrouter} sysctl net.ipv4.conf.veth0.forwarding=1 > /dev/null
+ip netns exec ${nsrouter} sysctl net.ipv4.conf.veth1.forwarding=1 > /dev/null
+
+sleep 3
+
+test_ping 10.0.2.1 dead:2::1 || exit 1
+check_drops || exit 1
+
+test_ping 10.0.2.99 dead:2::99 || exit 1
+check_drops || exit 1
+
+echo "PASS: fib expression did not cause unwanted packet drops"
+
+ip netns exec ${nsrouter} nft flush table inet filter
+
+ip -net ${ns1} route del default
+ip -net ${ns1} -6 route del default
+
+ip -net ${ns1} addr del 10.0.1.99/24 dev eth0
+ip -net ${ns1} addr del dead:1::99/64 dev eth0
+
+ip -net ${ns1} addr add 10.0.2.99/24 dev eth0
+ip -net ${ns1} addr add dead:2::99/64 dev eth0
+
+ip -net ${ns1} route add default via 10.0.2.1
+ip -net ${ns1} -6 route add default via dead:2::1
+
+ip -net ${nsrouter} addr add dead:2::1/64 dev veth0
+
+# switch to ruleset that doesn't log, this time
+# its expected that this does drop the packets.
+load_ruleset_count ${nsrouter}
+
+# ns1 has a default route, but nsrouter does not.
+# must not check return value, ping to 1.1.1.1 will
+# fail.
+check_fib_counter 0 ${nsrouter} 1.1.1.1 || exit 1
+check_fib_counter 0 ${nsrouter} 1c3::c01d || exit 1
+
+ip netns exec ${ns1} ping -c 1 -W 1 -q 1.1.1.1 > /dev/null
+check_fib_counter 1 ${nsrouter} 1.1.1.1 || exit 1
+
+sleep 2
+ip netns exec ${ns1} ping -c 3 -q 1c3::c01d > /dev/null
+check_fib_counter 3 ${nsrouter} 1c3::c01d || exit 1
+
+exit 0
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread* [PATCH net 3/3] netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local
2021-06-10 16:54 [PATCH net 0/3] Netfilter fixes for net Pablo Neira Ayuso
2021-06-10 16:54 ` [PATCH net 1/3] netfilter: nf_tables: initialize set before expression setup Pablo Neira Ayuso
2021-06-10 16:54 ` [PATCH net 2/3] selftests: netfilter: add fib test case Pablo Neira Ayuso
@ 2021-06-10 16:54 ` Pablo Neira Ayuso
2 siblings, 0 replies; 5+ messages in thread
From: Pablo Neira Ayuso @ 2021-06-10 16:54 UTC (permalink / raw)
To: netfilter-devel; +Cc: davem, netdev, kuba
From: Florian Westphal <fw@strlen.de>
The ip6tables rpfilter match has an extra check to skip packets with
"::" source address.
Extend this to ipv6 fib expression. Else ipv6 duplicate address detection
packets will fail rpf route check -- lookup returns -ENETUNREACH.
While at it, extend the prerouting check to also cover the ingress hook.
Closes: https://bugzilla.netfilter.org/show_bug.cgi?id=1543
Fixes: f6d0cbcf09c5 ("netfilter: nf_tables: add fib expression")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
net/ipv6/netfilter/nft_fib_ipv6.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/net/ipv6/netfilter/nft_fib_ipv6.c b/net/ipv6/netfilter/nft_fib_ipv6.c
index e204163c7036..92f3235fa287 100644
--- a/net/ipv6/netfilter/nft_fib_ipv6.c
+++ b/net/ipv6/netfilter/nft_fib_ipv6.c
@@ -135,6 +135,17 @@ void nft_fib6_eval_type(const struct nft_expr *expr, struct nft_regs *regs,
}
EXPORT_SYMBOL_GPL(nft_fib6_eval_type);
+static bool nft_fib_v6_skip_icmpv6(const struct sk_buff *skb, u8 next, const struct ipv6hdr *iph)
+{
+ if (likely(next != IPPROTO_ICMPV6))
+ return false;
+
+ if (ipv6_addr_type(&iph->saddr) != IPV6_ADDR_ANY)
+ return false;
+
+ return ipv6_addr_type(&iph->daddr) & IPV6_ADDR_LINKLOCAL;
+}
+
void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,
const struct nft_pktinfo *pkt)
{
@@ -163,10 +174,13 @@ void nft_fib6_eval(const struct nft_expr *expr, struct nft_regs *regs,
lookup_flags = nft_fib6_flowi_init(&fl6, priv, pkt, oif, iph);
- if (nft_hook(pkt) == NF_INET_PRE_ROUTING &&
- nft_fib_is_loopback(pkt->skb, nft_in(pkt))) {
- nft_fib_store_result(dest, priv, nft_in(pkt));
- return;
+ if (nft_hook(pkt) == NF_INET_PRE_ROUTING ||
+ nft_hook(pkt) == NF_INET_INGRESS) {
+ if (nft_fib_is_loopback(pkt->skb, nft_in(pkt)) ||
+ nft_fib_v6_skip_icmpv6(pkt->skb, pkt->tprot, iph)) {
+ nft_fib_store_result(dest, priv, nft_in(pkt));
+ return;
+ }
}
*dest = 0;
--
2.20.1
^ permalink raw reply related [flat|nested] 5+ messages in thread