From 196e355877a767674ea9c35af1686e642294885a Mon Sep 17 00:00:00 2001 From: Ian Rogers Date: Tue, 29 Aug 2023 17:05:45 -0700 Subject: [PATCH] perf pmu: Avoid uninitialized use of alias->str alias is allocated with malloc allowing uninitialized memory to be accessed. The initialization of str was moved late after it could have been updated by a JSON event, however, this create a potential for an uninitialized use. Fix this by assigning str to NULL early. Testing on ARM (Raspberry Pi) showed a memory leak in the same code so add a zfree. Fixes: f63a536f03a2f64f ("perf pmu: Merge JSON events with sysfs at load time") Reported-by: Arnaldo Carvalho de Melo Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ian Rogers Cc: Ingo Molnar Cc: James Clark Cc: Jing Zhang Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Peter Zijlstra Cc: Sumanth Korikkar Cc: Thomas Richter Link: https://lore.kernel.org/r/20230830000545.1638964-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/pmu.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index cde33e01959a..b3f8f3f1e900 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -532,6 +532,7 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name, if (!alias) return -ENOMEM; + alias->str = NULL; INIT_LIST_HEAD(&alias->terms); alias->scale = 1.0; alias->unit[0] = '\0'; @@ -593,6 +594,7 @@ static int perf_pmu__new_alias(struct perf_pmu *pmu, const char *name, ret += scnprintf(newval + ret, sizeof(newval) - ret, "%s=%s", term->config, term->val.str); } + zfree(&alias->str); alias->str = strdup(newval); if (!pe) pmu->sysfs_aliases++; -- 2.11.0