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 <[email protected]>
Signed-off-by: Ian Rogers <[email protected]>
Acked-by: Namhyung Kim <[email protected]>
Tested-by: Arnaldo Carvalho de Melo <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Alexander Shishkin <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: James Clark <[email protected]>
Cc: Jing Zhang <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Kan Liang <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Sumanth Korikkar <[email protected]>
Cc: Thomas Richter <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

0 files changed, 0 insertions, 0 deletions