[PATCH v2] tracing/synthetic: Free type string on error path

[Yu Peng]

parse_synth_field() builds a "__data_loc ..." type string before
assigning it to field->type. If the seq_buf check fails, the temporary
string is not owned by field and is leaked. Free it before leaving.

Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Yu Peng <pengyu@xxxxxxxxxx>
---
Changes in v2:
- Use __free(kfree) and no_free_ptr() as suggested by Steven.

 kernel/trace/trace_events_synth.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c
index e6871230bde96..ad2e70258291b 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -828,7 +828,7 @@ static struct synth_field *parse_synth_field(int argc, char **argv,
 	} else if (size == 0) {
 		if (synth_field_is_string(field->type) ||
 		    synth_field_is_stack(field->type)) {
-			char *type;
+			char *type __free(kfree) = NULL;
 
 			len = sizeof("__data_loc ") + strlen(field->type) + 1;
 			type = kzalloc(len, GFP_KERNEL);
@@ -844,7 +844,7 @@ static struct synth_field *parse_synth_field(int argc, char **argv,
 			s.buffer[s.len] = '\0';
 
 			kfree(field->type);
-			field->type = type;
+			field->type = no_free_ptr(type);
 
 			field->is_dynamic = true;
 			size = sizeof(u64);
-- 
2.43.0