[PATCH 3/5] tracing: Check that the synthetic event and field names are legal

From: Tom Zanussi
Date: Fri Oct 09 2020 - 11:17:30 EST


Call the is_good_name() function used by probe events to make sure
synthetic event and field names don't contain illegal characters and
cause unexpected parsing of synthetic event commands.

Fixes: 4b147936fa50 (tracing: Add support for 'synthetic' events)
Reported-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx>
Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx>
---
kernel/trace/trace_events_synth.c | 9 +++++++++
1 file changed, 9 insertions(+)

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index b19e2f4159ab..8c9d6e464da0 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -572,6 +572,10 @@ static struct synth_field *parse_synth_field(int argc, const char **argv,
ret = -ENOMEM;
goto free;
}
+ if (!is_good_name(field->name)) {
+ ret = -EINVAL;
+ goto free;
+ }

if (field_type[0] == ';')
field_type++;
@@ -1112,6 +1116,11 @@ static int __create_synth_event(int argc, const char *name, const char **argv)

mutex_lock(&event_mutex);

+ if (!is_good_name(name)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
event = find_synth_event(name);
if (event) {
ret = -EEXIST;
--
2.17.1