git: 8a14fcd23a20 - main - pf: fix a crash on sendfile()
- Go to: [ bottom of page ] [ top of archives ] [ this month ]
Date: Wed, 08 Jul 2026 07:52:13 UTC
The branch main has been updated by kp:
URL: https://cgit.FreeBSD.org/src/commit/?id=8a14fcd23a201944f3eb5086403d10cfe1fc128f
commit 8a14fcd23a201944f3eb5086403d10cfe1fc128f
Author: KUROSAWA Takahiro <takahiro.kurosawa@gmail.com>
AuthorDate: 2026-07-07 19:43:32 +0000
Commit: Kristof Provost <kp@FreeBSD.org>
CommitDate: 2026-07-08 07:23:17 +0000
pf: fix a crash on sendfile()
The network layer must not pass unmapped (M_EXTPG) mbufs to if_output()
of network interfaces without IFCAP_MEXTPG. pf should convert these
mbufs by mb_unmapped_to_ext() for such interfaces but it didn't.
The problem had occurred on sendfile because sendfile system call
uses unmapped mbufs for the file data.
Reported by: feld
Reviewed by: kp, glebius
Differential Revision: https://reviews.freebsd.org/D58021
---
sys/netpfil/pf/pf.c | 35 ++++++++
tests/sys/netpfil/pf/Makefile | 3 +-
tests/sys/netpfil/pf/unmapped_mbuf.sh | 145 ++++++++++++++++++++++++++++++++++
3 files changed, 182 insertions(+), 1 deletion(-)
diff --git a/sys/netpfil/pf/pf.c b/sys/netpfil/pf/pf.c
index c7d5e923d50b..10e73ce1e7b9 100644
--- a/sys/netpfil/pf/pf.c
+++ b/sys/netpfil/pf/pf.c
@@ -9980,6 +9980,21 @@ pf_route(struct pf_krule *r, struct ifnet *oifp,
pd->act.dnpipe = tmp;
}
+ /*
+ * If the output interface does not accept unmapped mbufs, convert
+ * them to mapped mbufs.
+ */
+ if ((ifp->if_capenable & IFCAP_MEXTPG) == 0) {
+ error = mb_unmapped_to_ext(m0, &md);
+ if (error)
+ goto done;
+ /*
+ * The first mbuf should not be reallocated because it is
+ * always mapped.
+ */
+ MPASS(m0 == md);
+ }
+
/*
* If small enough for interface, or the interface will take
* care of the fragmentation for us, we can just send directly.
@@ -10321,6 +10336,11 @@ pf_route6(struct pf_krule *r, struct ifnet *oifp,
}
if ((u_long)m0->m_pkthdr.len <= ifp->if_mtu) {
+ if ((ifp->if_capenable & IFCAP_MEXTPG) == 0) {
+ if (mb_unmapped_to_ext(m0, &md) != 0)
+ goto done;
+ MPASS(m0 == md);
+ }
md = m0;
pf_dummynet_route(pd, s, r, ifp, sintosa(&dst), &md);
if (md != NULL) {
@@ -11585,6 +11605,7 @@ pf_test(sa_family_t af, int dir, int pflags, struct ifnet *ifp, struct mbuf **m0
{
struct pfi_kkif *kif;
u_short action, reason = 0;
+ struct mbuf *m;
struct m_tag *mtag;
struct pf_krule *a = NULL, *r = &V_pf_default_rule;
struct pf_kstate *s = NULL;
@@ -11620,6 +11641,12 @@ pf_test(sa_family_t af, int dir, int pflags, struct ifnet *ifp, struct mbuf **m0
}
if (__predict_false(! M_WRITABLE(*m0))) {
+ /* Need to convert unmapped mbufs before calling m_unshare(). */
+ if (mb_unmapped_to_ext(*m0, &m) != 0) {
+ *m0 = NULL;
+ return (PF_DROP);
+ }
+ MPASS(*m0 == m);
*m0 = m_unshare(*m0, M_NOWAIT);
if (*m0 == NULL) {
return (PF_DROP);
@@ -11639,6 +11666,14 @@ pf_test(sa_family_t af, int dir, int pflags, struct ifnet *ifp, struct mbuf **m0
*m0 = NULL;
return (PF_PASS);
}
+
+ /*
+ * No need to call mb_unmapped_to_ext() here because it had
+ * already been called in pf_route()/pf_route6() and dummynet
+ * re-injected this packet.
+ */
+
+ M_ASSERTMAPPED(*m0);
(ifp->if_output)(ifp, *m0, sintosa(&pd.pf_mtag->dst), NULL);
*m0 = NULL;
return (PF_PASS);
diff --git a/tests/sys/netpfil/pf/Makefile b/tests/sys/netpfil/pf/Makefile
index ded0002768b0..7b2e32c09543 100644
--- a/tests/sys/netpfil/pf/Makefile
+++ b/tests/sys/netpfil/pf/Makefile
@@ -56,7 +56,8 @@ ATF_TESTS_SH+= altq \
synproxy \
table \
tcp \
- tos
+ tos \
+ unmapped_mbuf
ATF_TESTS_PYTEST+= frag4.py
ATF_TESTS_PYTEST+= frag6.py
diff --git a/tests/sys/netpfil/pf/unmapped_mbuf.sh b/tests/sys/netpfil/pf/unmapped_mbuf.sh
new file mode 100644
index 000000000000..d8005d12b44d
--- /dev/null
+++ b/tests/sys/netpfil/pf/unmapped_mbuf.sh
@@ -0,0 +1,145 @@
+#
+# SPDX-License-Identifier: BSD-2-Clause
+#
+# Copyright (c) 2026 KUROSAWA Takahiro <takahiro.kurosawa@gmail.com>
+#
+# 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.
+
+. $(atf_get_srcdir)/utils.subr
+
+HELPER=$(atf_get_srcdir)/../../common/sendfile_helper
+
+# pf must call mb_unmapped_to_ext() before passing an output mbuf to a network
+# interface if it does not accept unmapped mbufs as ip_output() does. These
+# tests make sure that unmapped mbufs are correctly converted to mapped ones
+# before pf passes mbufs to interfaces.
+
+atf_test_case "v4" "cleanup"
+v4_head() {
+ atf_set descr 'unmapped mbuf IPv4 test'
+ atf_set require.user root
+}
+
+v4_body() {
+ pft_init
+
+ l=$(vnet_mkepair)
+ vnet_mkjail a ${l}a
+ jexec a ifconfig ${l}a 192.0.2.1/24 up
+ vnet_mkjail b ${l}b
+ jexec b ifconfig ${l}b 192.0.2.2/24 up
+
+ # Sanity check
+ atf_check -s exit:0 -o ignore jexec a ping -c 1 192.0.2.2
+
+ jexec a pfctl -e
+ pft_set_rules a "pass out on ${l}a route-to (${l}a 192.0.2.2) all"
+ jexec b timeout 30s nc -4 -d -l 2345 > out &
+ sleep 1
+ atf_check -s exit:0 -o ignore \
+ jexec a ${HELPER} -c 192.0.2.2 -p 2345 ${HELPER} 0 512 0
+ wait
+ atf_check_equal $(dd bs=512 count=1 if=${HELPER} | sha256 -q) \
+ $(sha256 -q out)
+}
+
+v4_cleanup() {
+ pft_cleanup
+ rm -f out
+}
+
+atf_test_case "v6" "cleanup"
+v6_head() {
+ atf_set descr 'unmapped mbuf IPv6 test'
+ atf_set require.user root
+}
+
+v6_body() {
+ pft_init
+
+ l=$(vnet_mkepair)
+ vnet_mkjail a ${l}a
+ jexec a ifconfig ${l}a inet6 2001:db8::1/64 up
+ vnet_mkjail b ${l}b
+ jexec b ifconfig ${l}b inet6 2001:db8::2/64 up
+
+ # Sanity check
+ atf_check -s exit:0 -o ignore jexec a ping -c 1 2001:db8::2
+
+ jexec a pfctl -e
+ pft_set_rules a "pass out on ${l}a route-to (${l}a 2001:db8::2) all"
+ jexec b timeout 30s nc -6 -d -l 2345 > out &
+ sleep 1
+ atf_check -s exit:0 -o ignore \
+ jexec a ${HELPER} -c 2001:db8::2 -p 2345 ${HELPER} 0 512 0
+ wait
+ atf_check_equal $(dd bs=512 count=1 if=${HELPER} | sha256 -q) \
+ $(sha256 -q out)
+}
+
+v6_cleanup() {
+ pft_cleanup
+ rm -f out
+}
+
+atf_test_case "dummynet" "cleanup"
+dummynet_head() {
+ atf_set descr 'unmapped mbuf dummynet test'
+ atf_set require.user root
+}
+
+dummynet_body() {
+ pft_init
+
+ l=$(vnet_mkepair)
+ vnet_mkjail a ${l}a
+ jexec a ifconfig ${l}a 192.0.2.1/24 up
+ vnet_mkjail b ${l}b
+ jexec b ifconfig ${l}b 192.0.2.2/24 up
+
+ # Sanity check
+ atf_check -s exit:0 -o ignore jexec a ping -c 1 192.0.2.2
+
+ atf_check -s exit:0 -o ignore \
+ jexec a dnctl pipe 1 config delay 100
+ jexec a pfctl -e
+ pft_set_rules a "pass out on ${l}a route-to (${l}a 192.0.2.2) all dnpipe 1"
+ jexec b timeout 30s nc -4 -d -l 2345 > out &
+ sleep 1
+ atf_check -s exit:0 -o ignore \
+ jexec a ${HELPER} -c 192.0.2.2 -p 2345 ${HELPER} 0 512 0
+ wait
+ atf_check_equal $(dd bs=512 count=1 if=${HELPER} | sha256 -q) \
+ $(sha256 -q out)
+}
+
+dummynet_cleanup() {
+ pft_cleanup
+ rm -f out
+}
+
+atf_init_test_cases()
+{
+ atf_add_test_case "v4"
+ atf_add_test_case "v6"
+ atf_add_test_case "dummynet"
+}