Potential corner cases could cause a cpumap to be allocated with size 0, but an empty cpumap should be represented as NULL. Add a path in perf_cpu_map__alloc to ensure this. Suggested-by: James Clark <james.clark@xxxxxxx> Closes: https://lore.kernel.org/lkml/2cd09e7c-eb88-6726-6169-647dcd0a8101@xxxxxxx/ Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx> --- tools/lib/perf/cpumap.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/tools/lib/perf/cpumap.c b/tools/lib/perf/cpumap.c index ba49552952c5..cae799ad44e1 100644 --- a/tools/lib/perf/cpumap.c +++ b/tools/lib/perf/cpumap.c @@ -18,9 +18,13 @@ void perf_cpu_map__set_nr(struct perf_cpu_map *map, int nr_cpus) struct perf_cpu_map *perf_cpu_map__alloc(int nr_cpus) { - RC_STRUCT(perf_cpu_map) *cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus); + RC_STRUCT(perf_cpu_map) *cpus; struct perf_cpu_map *result; + if (nr_cpus == 0) + return NULL; + + cpus = malloc(sizeof(*cpus) + sizeof(struct perf_cpu) * nr_cpus); if (ADD_RC_CHK(result, cpus)) { cpus->nr = nr_cpus; refcount_set(&cpus->refcnt, 1); -- 2.43.0.594.gd9cf4e227d-goog
