[PATCH 4.19 27/44] tracing: Fix memory leak in create_filter()

From: Greg Kroah-Hartman
Date: Tue Dec 18 2018 - 11:41:43 EST


4.19-stable review patch. If anyone has any objections, please let me know.

------------------

From: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>

commit b61c19209c2c35ea2a2fe502d484703686eba98c upstream.

The create_filter() calls create_filter_start() which allocates a
"parse_error" descriptor, but fails to call create_filter_finish() that
frees it.

The op_stack and inverts in predicate_parse() were also not freed.

Found by kmemleak detector.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 80765597bc587 ("tracing: Rewrite filter logic to be simpler and faster")
Reviewed-by: Tom Zanussi <tom.zanussi@xxxxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
kernel/trace/trace_events_filter.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -570,11 +570,13 @@ predicate_parse(const char *str, int nr_
}
}

+ kfree(op_stack);
+ kfree(inverts);
return prog;
out_free:
kfree(op_stack);
- kfree(prog_stack);
kfree(inverts);
+ kfree(prog_stack);
return ERR_PTR(ret);
}

@@ -1718,6 +1720,7 @@ static int create_filter(struct trace_ev
err = process_preds(call, filter_string, *filterp, pe);
if (err && set_str)
append_filter_err(pe, *filterp);
+ create_filter_finish(pe);

return err;
}