Commit 8fbeb52a authored Oct 04, 2020 by Tom Zanussi Committed by Steven Rostedt (VMware) Oct 05, 2020

tracing: Fix parse_synth_field() error handling

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@google.com: changelog addition, first paragraph above ]

Link: https://lkml.kernel.org/r/9b6946d9776b2eeb43227678158196de1c3c6e1d.1601848695.git.zanussi@kernel.org



Fixes: 4b147936 (tracing: Add support for 'synthetic' events)
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Axel Rasmussen <axelrasmussen@google.com>
Signed-off-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

parent 4a4a56b4

kernel/trace/trace_events_synth.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -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;

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