git: 7ee1bdd094d3 - main - libdtrace: Fix an off-by-one in the priority queue implementation

The branch main has been updated by markj:

URL: https://cgit.FreeBSD.org/src/commit/?id=7ee1bdd094d376fdc547e8ca33e472f1d37a7d79

commit 7ee1bdd094d376fdc547e8ca33e472f1d37a7d79
Author:     Mark Johnston <markj@FreeBSD.org>
AuthorDate: 2025-03-10 03:00:42 +0000
Commit:     Mark Johnston <markj@FreeBSD.org>
CommitDate: 2025-03-10 03:00:42 +0000

    libdtrace: Fix an off-by-one in the priority queue implementation
    
    The zero'th index in the array is unused, so a priority queue of N elements
    needs N+1 array slots.  Fix the allocation.
    
    Also fix the assertion in dt_pq_insert(): the assertion needs to be checked
    after incrementing the count of items in the priority queue, otherwise it can
    miss an overflow.
    
    Reported by:    CHERI
    MFC after:      2 weeks
    Sponsored by:   Innovate UK
    Differential Revision:  https://reviews.freebsd.org/D49242
---
 cddl/contrib/opensolaris/lib/libdtrace/common/dt_pq.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pq.c b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pq.c
index 0cd556abd8f5..ffbac8b6ea1e 100644
--- a/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pq.c
+++ b/cddl/contrib/opensolaris/lib/libdtrace/common/dt_pq.c
@@ -37,7 +37,7 @@ dt_pq_init(dtrace_hdl_t *dtp, uint_t size, dt_pq_value_f value_cb, void *cb_arg)
 	if ((p = dt_zalloc(dtp, sizeof (dt_pq_t))) == NULL)
 		return (NULL);
 
-	p->dtpq_items = dt_zalloc(dtp, size * sizeof (p->dtpq_items[0]));
+	p->dtpq_items = dt_zalloc(dtp, (size + 1) * sizeof (p->dtpq_items[0]));
 	if (p->dtpq_items == NULL) {
 		dt_free(dtp, p);
 		return (NULL);
@@ -73,9 +73,9 @@ dt_pq_insert(dt_pq_t *p, void *item)
 {
 	uint_t i;
 
-	assert(p->dtpq_last < p->dtpq_size);
-
 	i = p->dtpq_last++;
+	assert(i <= p->dtpq_size);
+
 	p->dtpq_items[i] = item;
 
 	while (i > 1 && dt_pq_getvalue(p, i) < dt_pq_getvalue(p, i / 2)) {