From: Tom Zanussi <zanussi@xxxxxxxxxx> [ Upstream commit 8fbeb52a598c7ab5aa603d6bb083b8a8d16d607a ] synth_field_size() returns either a positive size or an error (zero or a negative value). However, the existing code assumes the only error value is 0. It doesn't handle negative error codes, as it assigns directly to field->size (a size_t; unsigned), thereby interpreting the error code as a valid size instead. Do the test before assignment to field->size. [ axelrasmussen@xxxxxxxxxx: changelog addition, first paragraph above ] Link: https://lkml.kernel.org/r/9b6946d9776b2eeb43227678158196de1c3c6e1d.1601848695.git.zanussi@xxxxxxxxxx Fixes: 4b147936fa50 (tracing: Add support for 'synthetic' events) Reviewed-by: Masami Hiramatsu <mhiramat@xxxxxxxxxx> Tested-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> Signed-off-by: Tom Zanussi <zanussi@xxxxxxxxxx> Signed-off-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- kernel/trace/trace_events_synth.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_synth.c b/kernel/trace/trace_events_synth.c index c6cca0d1d5840..46a96686e93c6 100644 --- a/kernel/trace/trace_events_synth.c +++ b/kernel/trace/trace_events_synth.c @@ -465,6 +465,7 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, struct synth_field *field; const char *prefix = NULL, *field_type = argv[0], *field_name, *array; int len, ret = 0; + ssize_t size; if (field_type[0] == ';') field_type++; @@ -520,11 +521,12 @@ static struct synth_field *parse_synth_field(int argc, const char **argv, field->type[len - 1] = '\0'; } - field->size = synth_field_size(field->type); - if (!field->size) { + size = synth_field_size(field->type); + if (size <= 0) { ret = -EINVAL; goto free; } + field->size = size; if (synth_field_is_string(field->type)) field->is_string = true; -- 2.25.1
