From 93fd7adf1a47c61ef81b33c8fdd9cb4e4ea0bdcb Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 8 Sep 2026 15:07:20 -0700 Subject: perf stat: Avoid uninitialized memory read on error If has_supported_counters fails then msg was passed to ui__error regardless of whether an error was written into msg leading to reading uninitialized memory. Avoid this by always terminating msg at initialization. Opportunistically reduce the scope of msg to make its use clearer. Fixes: c9a8c343ef2f ("perf stat: When no events, don't report an error if there is none") Signed-off-by: Ian Rogers Link: https://lore.kernel.org/r/20260908220720.564614-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-stat.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index c50cf230f16e..37752d6bfef4 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -777,7 +777,6 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) int interval = stat_config.interval; int times = stat_config.times; int timeout = stat_config.timeout; - char msg[BUFSIZ]; unsigned long long t0, t1; struct evsel *counter; size_t l; @@ -908,6 +907,9 @@ static int __run_perf_stat(int argc, const char **argv, int run_idx) } } if (!has_supported_counters && !stat_config.null_run) { + char msg[BUFSIZ]; + + msg[0] = '\0'; if (open_err) { evsel__open_strerror(evlist__first(evsel_list), &target, open_err, msg, sizeof(msg)); -- cgit v1.2.3