[igt-dev] [PATCH i-g-t v3] tests/testdisplay: fix heap overflow

Simon Ser
2019-03-20T11:49:01Z

v2: also simplify the code by using dirname(3).

v3: dirname may modify in-place its argument, duplicate the string

Signed-off-by: Simon Ser <simon.ser@intel.com>
---

We can't free() the return value of dirname(), because it might be
statically allocated.

Also, we don't want to chdir(NULL).

tests/testdisplay.c | 22 ++++++++--------------
1 file changed, 8 insertions(+), 14 deletions(-)

diff --git a/tests/testdisplay.c b/tests/testdisplay.c
index b3657264..67d1b68a 100644
--- a/tests/testdisplay.c
+++ b/tests/testdisplay.c
@@ -51,6 +51,7 @@
#include <cairo.h>
#include <errno.h>
#include <getopt.h>
+#include <libgen.h>
#include <math.h>
#include <stdint.h>
#include <stdbool.h>
@@ -563,24 +564,17 @@ static gboolean input_event(GIOChannel *source, GIOCondition condition,
return TRUE;
}

-static void enter_exec_path( char **argv )
+static void enter_exec_path(const char **argv)
{
- char *exec_path = NULL;
- char *pos = NULL;
- short len_path = 0;
+ char *argv0, *exec_path;
int ret;

- len_path = strlen( argv[0] );
- exec_path = (char*) malloc(len_path);
-
- memcpy(exec_path, argv[0], len_path);
- pos = strrchr(exec_path, '/');
- if (pos != NULL)
- *(pos+1) = '\0';
-
+ argv0 = strdup(argv[0]);
+ igt_assert(argv0);
+ exec_path = dirname(argv0);
ret = chdir(exec_path);
igt_assert_eq(ret, 0);
- free(exec_path);
+ free(argv0);
}

static void restore_termio_mode(int sig)
@@ -626,7 +620,7 @@ int main(int argc, char **argv)

igt_skip_on_simulation();

- enter_exec_path( argv );
+ enter_exec_path((const char **) argv);

while ((c = getopt_long(argc, argv, optstr, long_opts, NULL)) != -1) {
switch (c) {
--
2.21.0

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