From: Adrian Hunter <adrian.hunter@xxxxxxxxx> commit 2e828582b81f5bc76a4fe8e7812df259ab208302 upstream. parse_events() is often called with parse_events_error set to NULL. Make parse_events_error__handle() not segfault in that case. A subsequent patch changes to avoid passing NULL in the first place. Fixes: 43eb05d066795bdf ("perf tests: Support 'Track with sched_switch' test for hybrid") Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx> Cc: Ian Rogers <irogers@xxxxxxxxxx> Cc: Jin Yao <yao.jin@xxxxxxxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Link: https://lore.kernel.org/r/20220809080702.6921-2-adrian.hunter@xxxxxxxxx Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- tools/perf/util/parse-events.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -2391,9 +2391,12 @@ void parse_events_error__exit(struct par void parse_events_error__handle(struct parse_events_error *err, int idx, char *str, char *help) { - if (WARN(!str, "WARNING: failed to provide error string\n")) { - free(help); - return; + if (WARN(!str, "WARNING: failed to provide error string\n")) + goto out_free; + if (!err) { + /* Assume caller does not want message printed */ + pr_debug("event syntax error: %s\n", str); + goto out_free; } switch (err->num_errors) { case 0: @@ -2419,6 +2422,11 @@ void parse_events_error__handle(struct p break; } err->num_errors++; + return; + +out_free: + free(str); + free(help); } #define MAX_WIDTH 1000