git: a3d974082549 - main - pf: make sure the rule tree is allocated in DIOCCHANGERULE

The branch main has been updated by mjg:

URL: https://cgit.FreeBSD.org/src/commit/?id=a3d9740825499c8a495261e09b7f9e49f6b4ac81

commit a3d9740825499c8a495261e09b7f9e49f6b4ac81
Author:     Mateusz Guzik <mjg@FreeBSD.org>
AuthorDate: 2022-05-27 22:15:34 +0000
Commit:     Mateusz Guzik <mjg@FreeBSD.org>
CommitDate: 2022-05-30 14:09:53 +0000

    pf: make sure the rule tree is allocated in DIOCCHANGERULE
    
    Original patch by:      peter
    Sponsored by:   Rubicon Communications, LLC ("Netgate")
---
 sys/netpfil/pf/pf_ioctl.c | 40 +++++++++++++++++++++++++++++++++++++---
 1 file changed, 37 insertions(+), 3 deletions(-)

diff --git a/sys/netpfil/pf/pf_ioctl.c b/sys/netpfil/pf/pf_ioctl.c
index 5185e457867e..745b9b69060b 100644
--- a/sys/netpfil/pf/pf_ioctl.c
+++ b/sys/netpfil/pf/pf_ioctl.c
@@ -1152,6 +1152,25 @@ out:
 }
 #endif /* ALTQ */
 
+static struct pf_krule_global *
+pf_rule_tree_alloc(int flags)
+{
+	struct pf_krule_global *tree;
+
+	tree = malloc(sizeof(struct pf_krule_global), M_TEMP, flags);
+	if (tree == NULL)
+		return (NULL);
+	RB_INIT(tree);
+	return (tree);
+}
+
+static void
+pf_rule_tree_free(struct pf_krule_global *tree)
+{
+
+	free(tree, M_TEMP);
+}
+
 static int
 pf_begin_rules(u_int32_t *ticket, int rs_num, const char *anchor)
 {
@@ -1163,16 +1182,15 @@ pf_begin_rules(u_int32_t *ticket, int rs_num, const char *anchor)
 
 	if (rs_num < 0 || rs_num >= PF_RULESET_MAX)
 		return (EINVAL);
-	tree = malloc(sizeof(struct pf_krule_global), M_TEMP, M_NOWAIT);
+	tree = pf_rule_tree_alloc(M_NOWAIT);
 	if (tree == NULL)
 		return (ENOMEM);
-	RB_INIT(tree);
 	rs = pf_find_or_create_kruleset(anchor);
 	if (rs == NULL) {
 		free(tree, M_TEMP);
 		return (EINVAL);
 	}
-	free(rs->rules[rs_num].inactive.tree, M_TEMP);
+	pf_rule_tree_free(rs->rules[rs_num].inactive.tree);
 	rs->rules[rs_num].inactive.tree = tree;
 
 	while ((rule = TAILQ_FIRST(rs->rules[rs_num].inactive.ptr)) != NULL) {
@@ -3455,6 +3473,22 @@ DIOCGETRULENV_error:
 		if (rs_num >= PF_RULESET_MAX)
 			ERROUT(EINVAL);
 
+		/*
+		 * XXXMJG: there is no guarantee that the ruleset was
+		 * created by the usual route of calling DIOCXBEGIN.
+		 * As a result it is possible the rule tree will not
+		 * be allocated yet. Hack around it by doing it here.
+		 * Note it is fine to let the tree persist in case of
+		 * error as it will be freed down the road on future
+		 * updates (if need be).
+		 */
+		if (ruleset->rules[rs_num].active.tree == NULL) {
+			ruleset->rules[rs_num].active.tree = pf_rule_tree_alloc(M_NOWAIT);
+			if (ruleset->rules[rs_num].active.tree == NULL) {
+				ERROUT(ENOMEM);
+			}
+		}
+
 		if (pcr->action == PF_CHANGE_GET_TICKET) {
 			pcr->ticket = ++ruleset->rules[rs_num].active.ticket;
 			ERROUT(0);