From 98582ce381836a5873c7e18a595c4e4621f9cbd6 Mon Sep 17 00:00:00 2001
From: Kristof Provost <kp@FreeBSD.org>
Date: Sun, 19 Apr 2020 16:10:20 +0000
Subject: [PATCH] pf: Improve ioctl() input validation

Both DIOCCHANGEADDR and DIOCADDADDR take a struct pf_pooladdr from
userspace. They failed to validate the dyn pointer contained in its
struct pf_addr_wrap member structure.

This triggered assertion failures under fuzz testing in
pfi_dynaddr_setup(). Happily the dyn variable was overruled there, but
we should verify that it's set to NULL anyway.

Reported-by:	syzbot+93e93150bc29f9b4b85f@syzkaller.appspotmail.com
Reviewed by:	emaste
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D24431
---
 sys/netpfil/pf/pf_ioctl.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c
index a1b973edb557..af7116befff7 100644
--- a/sys/netpfil/pf/pf_ioctl.c
+++ b/sys/netpfil/pf/pf_ioctl.c
@@ -2643,6 +2643,10 @@ DIOCGETSTATES_full:
 			error = EINVAL;
 			break;
 		}
+		if (pp->addr.addr.p.dyn != NULL) {
+			error = EINVAL;
+			break;
+		}
 		pa = malloc(sizeof(*pa), M_PFRULE, M_WAITOK);
 		bcopy(&pp->addr, pa, sizeof(struct pf_pooladdr));
 		if (pa->ifname[0])
@@ -2742,6 +2746,10 @@ DIOCGETSTATES_full:
 			error = EINVAL;
 			break;
 		}
+		if (pca->addr.addr.p.dyn != NULL) {
+			error = EINVAL;
+			break;
+		}
 
 		if (pca->action != PF_CHANGE_REMOVE) {
 #ifndef INET