Messages in this thread | | | From | Namhyung Kim <> | Date | Tue, 29 Aug 2023 19:23:58 -0700 | Subject | Re: [PATCH v1] perf pmu: Avoid uninitialized use of alias->str |
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Hi Ian,
On Tue, Aug 29, 2023 at 5:05 PM Ian Rogers <irogers@google.com> wrote: > > 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: f63a536f03a2 ("perf pmu: Merge JSON events with sysfs at load time") > Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Thanks, Namhyung
> --- > 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++; > -- > 2.42.0.rc2.253.gd59a3bf2b4-goog >
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