From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Fri, 21 Dec 2018 23:13:46 +0000 (+0100)
Subject: Avoid a time-to-check-versus-time-of-use error on mkdir().
X-Git-Tag: 1.8.1~45
X-Git-Url: https://git.sesse.net/?p=nageru;a=commitdiff_plain;h=b168e72fcdcd17be5c578f2232e40c2347c3ff98

Avoid a time-to-check-versus-time-of-use error on mkdir().

Found by Coverity Scan. Not relevant in practice, since we do not
support running on untrusted data.
---

diff --git a/futatabi/main.cpp b/futatabi/main.cpp
index 33a486a..3146aa5 100644
--- a/futatabi/main.cpp
+++ b/futatabi/main.cpp
@@ -200,13 +200,11 @@ int main(int argc, char **argv)
 
 	string frame_dir = global_flags.working_directory + "/frames";
 
-	struct stat st;
-	if (stat(frame_dir.c_str(), &st) == -1) {
+	if (mkdir(frame_dir.c_str(), 0777) == 0) {
 		fprintf(stderr, "%s does not exist, creating it.\n", frame_dir.c_str());
-		if (mkdir(frame_dir.c_str(), 0777) == -1) {
-			perror(global_flags.working_directory.c_str());
-			exit(1);
-		}
+	} else if (errno != EEXIST) {
+		perror(global_flags.working_directory.c_str());
+		exit(1);
 	}
 
 	avformat_network_init();