git: c23eda976a8a - main - pf: fix possible pd->pcksum NULL deref
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Date: Fri, 05 Sep 2025 19:54:59 UTC
The branch main has been updated by kp:
URL: https://cgit.FreeBSD.org/src/commit/?id=c23eda976a8aad6bbd6c2042fa2ba1f0bc640e19
commit c23eda976a8aad6bbd6c2042fa2ba1f0bc640e19
Author: Kristof Provost <kp@FreeBSD.org>
AuthorDate: 2025-09-02 13:14:49 +0000
Commit: Kristof Provost <kp@FreeBSD.org>
CommitDate: 2025-09-05 19:54:12 +0000
pf: fix possible pd->pcksum NULL deref
Ensure that we always populate pcksum, not just for TCP/UDP/SCTP/ICMP.
We may end up using it (through pf_change_ap()) if we're doing NAT, so
ensure it's available even if it's sometimes just a dummy variable.
Reported-by: syzbot+3e73a7cba8cb6cd46f90@syzkaller.appspotmail.com
MFC after: 1 week
Sponsored by: Rubicon Communications, LLC ("Netgate")
---
sys/netpfil/pf/pf.c | 14 ++++++++
tests/sys/netpfil/pf/Makefile | 1 +
tests/sys/netpfil/pf/nat44.py | 76 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 91 insertions(+)
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
index 242152f17db0..3a047ea44c47 100644
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -8854,6 +8854,11 @@ pf_test_state_icmp(struct pf_kstate **state, struct pf_pdesc *pd,
default: {
int action;
+ /*
+ * Placeholder value, so future calls to pf_change_ap()
+ * don't try to update a NULL checksum pointer.
+ */
+ pd->pcksum = &pd->sctp_dummy_sum;
key.af = pd2.af;
key.proto = pd2.proto;
pf_addrcpy(&key.addr[pd2.sidx], pd2.src, key.af);
@@ -10614,6 +10619,13 @@ pf_setup_pdesc(sa_family_t af, int dir, struct pf_pdesc *pd, struct mbuf **m0,
break;
}
#endif /* INET6 */
+ default:
+ /*
+ * Placeholder value, so future calls to pf_change_ap() don't
+ * try to update a NULL checksum pointer.
+ */
+ pd->pcksum = &pd->sctp_dummy_sum;
+ break;
}
if (pd->sport)
@@ -10621,6 +10633,8 @@ pf_setup_pdesc(sa_family_t af, int dir, struct pf_pdesc *pd, struct mbuf **m0,
if (pd->dport)
pd->odport = pd->ndport = *pd->dport;
+ MPASS(pd->pcksum != NULL);
+
return (0);
}
diff --git a/tests/sys/netpfil/pf/Makefile b/tests/sys/netpfil/pf/Makefile
index 616ffe560b3a..9f993eec61d0 100644
--- a/tests/sys/netpfil/pf/Makefile
+++ b/tests/sys/netpfil/pf/Makefile
@@ -61,6 +61,7 @@ ATF_TESTS_PYTEST+= header.py
ATF_TESTS_PYTEST+= icmp.py
ATF_TESTS_PYTEST+= igmp.py
ATF_TESTS_PYTEST+= mld.py
+ATF_TESTS_PYTEST+= nat44.py
ATF_TESTS_PYTEST+= nat64.py
ATF_TESTS_PYTEST+= nat66.py
ATF_TESTS_PYTEST+= return.py
diff --git a/tests/sys/netpfil/pf/nat44.py b/tests/sys/netpfil/pf/nat44.py
new file mode 100644
index 000000000000..d69e794a62c3
--- /dev/null
+++ b/tests/sys/netpfil/pf/nat44.py
@@ -0,0 +1,76 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2025 Rubicon Communications, LLC (Netgate)
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+# 1. Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+# SUCH DAMAGE.
+
+import pytest
+from atf_python.sys.net.tools import ToolsHelper
+from atf_python.sys.net.vnet import VnetTestTemplate
+
+class TestNAT44(VnetTestTemplate):
+ REQUIRED_MODULES = [ "pf" ]
+ TOPOLOGY = {
+ "vnet1": {"ifaces": ["if1"]},
+ "vnet2": {"ifaces": ["if1", "if2"]},
+ "vnet3": {"ifaces": ["if2"]},
+ "if1": {"prefixes4": [("192.0.2.2/24", "192.0.2.1/24")]},
+ "if2": {"prefixes4": [("198.51.100.1/24", "198.51.100.2")]},
+ }
+
+ def vnet2_handler(self, vnet):
+ outifname = vnet.iface_alias_map["if2"].name
+ ToolsHelper.print_output("/sbin/sysctl net.inet.ip.forwarding=1")
+
+ ToolsHelper.print_output("/sbin/pfctl -e")
+ ToolsHelper.print_output("/sbin/pfctl -x loud")
+ ToolsHelper.pf_rules([
+ "set reassemble yes",
+ "nat on {} inet from 192.0.2.0/24 -> ({})".format(outifname, outifname),
+ "pass"])
+
+ def vnet3_handler(self, vnet):
+ pass
+
+ @pytest.mark.require_user("root")
+ @pytest.mark.require_progs(["scapy"])
+ def test_nat_igmp(self):
+ "Verify that NAT translation of !(TCP|UDP|SCTP|ICMP) doesn't panic"
+ ToolsHelper.print_output("/sbin/route add default 192.0.2.1")
+ ToolsHelper.print_output("ping -c 3 198.51.100.2")
+
+ # Import in the correct vnet, so at to not confuse Scapy
+ import scapy.all as sp
+ import scapy.contrib as sc
+ import scapy.contrib.igmp
+
+ pkt = sp.IP(dst="198.51.100.2", ttl=64) \
+ / sc.igmp.IGMP(type=0x11, mrcode=1)
+ sp.send(pkt)
+
+ # This time we'll hit an existing state
+ pkt = sp.IP(dst="198.51.100.2", ttl=64) \
+ / sc.igmp.IGMP(type=0x11, mrcode=1)
+ reply = sp.sr1(pkt, timeout=3)
+ if reply:
+ reply.show()