linux-kernel - [PATCH 2/5] plugin:python: check asprintf() errors

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Message-Id: <20170423102258.21609-3-federico.vaga@vaga.pv.it>
Date:   Sun, 23 Apr 2017 12:22:55 +0200
From:   Federico Vaga <federico.vaga@...a.pv.it>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     LKML <linux-kernel@...r.kernel.org>,
        Federico Vaga <federico.vaga@...a.pv.it>
Subject: [PATCH 2/5] plugin:python: check asprintf() errors

The code was validating the string but the man page for asprintf(3)
says clearly:

--------
If memory allocation wasn't possible, or some other error occurs,
these functions  will return -1, and the contents of strp are undefined.
--------

So, we cannot really rely on the returned string pointer.

Signed-off-by: Federico Vaga <federico.vaga@...a.pv.it>
---
 plugin_python.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/plugin_python.c b/plugin_python.c
index d3da8b0..2997679 100644
--- a/plugin_python.c
+++ b/plugin_python.c
@@ -24,6 +24,7 @@ static int load_plugin(struct pevent *pevent, const char *path,
 			const char *name, void *data)
 {
 	PyObject *globals = data;
+	int err;
 	int len = strlen(path) + strlen(name) + 2;
 	int nlen = strlen(name) + 1;
 	char *full = malloc(len);
@@ -41,9 +42,9 @@ static int load_plugin(struct pevent *pevent, const char *path,
 	strcpy(n, name);
 	n[nlen - 4] = '\0';
 
-	asprintf(&load, pyload, full, n);
-	if (!load)
-		return -ENOMEM;
+	err = asprintf(&load, pyload, full, n);
+	if (err < 0)
+		return err;
 
 	res = PyRun_String(load, Py_file_input, globals, globals);
 	if (!res) {
-- 
2.9.3