[PATCH next] perf tools: fix potential memleak in perf events parser

From: Chen Wandun
Date: Wed Jun 10 2020 - 21:43:01 EST


Fix potential memory leak in function parse_events_term__sym_hw()
and parse_events_term__clone().

1. Free memory when errors occur.
2. Function new_term may return error, so it is need to free memory
when the return value is negative.

Signed-off-by: Chen Wandun <chenwandun@xxxxxxxxxx>
---
tools/perf/util/parse-events.c | 40 +++++++++++++++++++++++++++++-----
1 file changed, 34 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 3decbb203846..3491c18edd71 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -2947,6 +2947,7 @@ int parse_events_term__sym_hw(struct parse_events_term **term,
.type_term = PARSE_EVENTS__TERM_TYPE_USER,
.config = config,
};
+ int ret;

if (!temp.config) {
temp.config = strdup("event");
@@ -2957,9 +2958,20 @@ int parse_events_term__sym_hw(struct parse_events_term **term,
sym = &event_symbols_hw[idx];

str = strdup(sym->symbol);
- if (!str)
+ if (!str) {
+ if (!config)
+ free(temp.config);
return -ENOMEM;
- return new_term(term, &temp, str, 0);
+ }
+
+ ret = new_term(term, &temp, str, 0);
+ if (ret < 0) {
+ free(str);
+ if (!config)
+ free(temp.config);
+ }
+
+ return ret;
}

int parse_events_term__clone(struct parse_events_term **new,
@@ -2973,19 +2985,35 @@ int parse_events_term__clone(struct parse_events_term **new,
.err_term = term->err_term,
.err_val = term->err_val,
};
+ int ret;

if (term->config) {
temp.config = strdup(term->config);
if (!temp.config)
return -ENOMEM;
}
- if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM)
- return new_term(new, &temp, NULL, term->val.num);
+ if (term->type_val == PARSE_EVENTS__TERM_TYPE_NUM) {
+ ret = new_term(new, &temp, NULL, term->val.num);
+ if (ret < 0 && term->config)
+ free(temp.config);
+ return ret;
+ }

str = strdup(term->val.str);
- if (!str)
+ if (!str) {
+ if (term->config)
+ free(temp.config);
return -ENOMEM;
- return new_term(new, &temp, str, 0);
+ }
+
+ ret = new_term(new, &temp, str, 0);
+ if (ret < 0) {
+ free(str);
+ if (term->config)
+ free(temp.config);
+ }
+
+ return ret;
}

void parse_events_term__delete(struct parse_events_term *term)
--
2.17.1