Commit 54ef362e authored May 07, 2024 by Arnaldo Carvalho de Melo

perf callchain: Use zfree() to avoid possibly accessing dangling pointers

When freeing a->b it is good practice to set a->b to NULL using
zfree(&a->b) so that when we have a bug where a reference to a freed 'a'
pointer is kept somewhere, we can more quickly cause a segfault if some
code tries to use a->b.

Convert one such case in the callchain code.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/lkml/ZjmcGobQ8E52EyjJ@x1

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 69fb6eab

tools/perf/util/callchain.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -606,7 +606,7 @@ fill_node(struct callchain_node node, struct callchain_cursor cursor)
		call->brtype_stat = zalloc(sizeof(*call->brtype_stat));
		if (!call->brtype_stat) {
		perror("not enough memory for the code path branch statistics");
		free(call->brtype_stat);
		zfree(&call->brtype_stat);
		return -ENOMEM;
		}
		}