Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
From:   Tom Zanussi <zanussi@kernel.org>
To:     rostedt@goodmis.org, axelrasmussen@google.com
Cc:     mhiramat@kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/3] tracing: Fix parse_synth_field() error handling
Date:   Tue, 29 Sep 2020 15:33:40 -0500
Message-Id: <834e9060c2e7e3272e25d8bfc6e7566639c18aa9.1601410890.git.zanussi@kernel.org>
In-Reply-To: <cover.1601410890.git.zanussi@kernel.org>
References: <cover.1601410890.git.zanussi@kernel.org>
In-Reply-To: <cover.1601410890.git.zanussi@kernel.org>
References: <cover.1601410890.git.zanussi@kernel.org>
Precedence: bulk

synth_field_size() returns either the size or an error.  However, the
code assigns the return val to ssize_t which is unsigned, and then
tests whether it's less than 0, which it isn't so discards the error.

Do the test before assignment to field->size.

Signed-off-by: Tom Zanussi <zanussi@kernel.org>
---
 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 a9cd7793f7ea..6e7282c7b530 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;
+	int 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;
-- 
2.17.1