From 11ff9bcd7dfeefa6a9a9fcd4c7775b8066c46a31 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Wed, 12 Apr 2023 09:50:08 -0300 Subject: [PATCH] perf metricgroups: Use zfree() to reduce chances of use after free Do defensive programming by using zfree() to initialize freed pointers to NULL, so that eventual use after free result in a NULL pointer deref instead of more subtle behaviour. This file already used zfree() in other places, so this just plugs some leftovers. Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/metricgroup.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c index 5783f4c2d1ef..4b9a16291b96 100644 --- a/tools/perf/util/metricgroup.c +++ b/tools/perf/util/metricgroup.c @@ -90,9 +90,9 @@ static void metric_event_delete(struct rblist *rblist __maybe_unused, struct metric_expr *expr, *tmp; list_for_each_entry_safe(expr, tmp, &me->head, nd) { - free((char *)expr->metric_name); - free(expr->metric_refs); - free(expr->metric_events); + zfree(&expr->metric_name); + zfree(&expr->metric_refs); + zfree(&expr->metric_events); free(expr); } @@ -192,9 +192,9 @@ static void metric__free(struct metric *m) if (!m) return; - free(m->metric_refs); + zfree(&m->metric_refs); expr__ctx_free(m->pctx); - free((char *)m->modifier); + zfree(&m->modifier); evlist__delete(m->evlist); free(m); } @@ -617,7 +617,7 @@ static int decode_all_metric_ids(struct evlist *perf_evlist, const char *modifie if (strstr(ev->name, "metric-id=")) { bool has_slash = false; - free(ev->name); + zfree(&ev->name); for (cur = strchr(sb.buf, '@') ; cur; cur = strchr(++cur, '@')) { *cur = '/'; has_slash = true; @@ -1760,7 +1760,7 @@ int metricgroup__copy_metric_events(struct evlist *evlist, struct cgroup *cgrp, alloc_size = sizeof(*new_expr->metric_events); new_expr->metric_events = calloc(nr + 1, alloc_size); if (!new_expr->metric_events) { - free(new_expr->metric_refs); + zfree(&new_expr->metric_refs); free(new_expr); return -ENOMEM; } @@ -1770,8 +1770,8 @@ int metricgroup__copy_metric_events(struct evlist *evlist, struct cgroup *cgrp, evsel = old_expr->metric_events[idx]; evsel = evlist__find_evsel(evlist, evsel->core.idx); if (evsel == NULL) { - free(new_expr->metric_events); - free(new_expr->metric_refs); + zfree(&new_expr->metric_events); + zfree(&new_expr->metric_refs); free(new_expr); return -EINVAL; } -- 2.49.0