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 <acme@redhat.com> Signed-off-by: Ian Rogers <irogers@google.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@arm.com> Cc: Jing Zhang <renyu.zj@linux.alibaba.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Kan Liang <kan.liang@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sumanth Korikkar <sumanthk@linux.ibm.com> Cc: Thomas Richter <tmricht@linux.ibm.com> Link: https://lore.kernel.org/r/20230830000545.1638964-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>