Fix a fd leak in socketpair():

- Close the new file objects created during socketpair() if the copyout of
  the new file descriptors fails.
- Add a test to the socketpair regression test for this edge case.

1 files changed, 33 insertions, 0 deletions

diff --git a/tools/regression/sockets/socketpair/socketpair.c b/tools/regression/sockets/socketpair/socketpair.c
index a1d0946..5f46476 100644
--- a/tools/regression/sockets/socketpair/socketpair.c
+++ b/tools/regression/sockets/socketpair/socketpair.c
@@ -49,6 +49,7 @@
 int
 main(int argc, char *argv[])
 {
+	int fd1, fd2, fd3;
 	int sv[2];
 
 	/*
@@ -123,6 +124,38 @@ main(int argc, char *argv[])
 		fprintf(stderr, "FAIL\n");
 	}
 
+	/*
+	 * Check for sequential fd allocation, and give up early if not.
+	 */
+	fd1 = dup(STDIN_FILENO);
+	fd2 = dup(STDIN_FILENO);
+	if (fd2 != fd1 + 1) {
+		fprintf(stderr, "Non-sequential fd allocation\n");
+		fprintf(stderr, "FAIL\n");
+		exit(-1);
+	}
+
+	/* Allocate a socketpair using a bad destination address. */
+	if (socketpair(PF_UNIX, SOCK_DGRAM, 0, NULL) == 0) {
+		fprintf(stderr, "socketpair(PF_UNIX, SOCK_DGRAM, NULL): opened\n");
+		fprintf(stderr, "FAIL\n");
+		exit(-1);
+	}
+	if (errno != EFAULT) {
+		fprintf(stderr, "socketpair(PF_UNIX, SOCK_DGRAM, NULL): %s\n",
+		    strerror(errno));
+		fprintf(stderr, "FAIL\n");
+		exit(-1);
+	}
+
+	/* Allocate a file descriptor and make sure it's fd2+1. */
+	fd3 = dup(STDIN_FILENO);
+	if (fd3 != fd2 + 1) {
+		fprintf(stderr, "socketpair(..., NULL) allocated descriptors\n");
+		fprintf(stderr, "FAIL\n");
+		exit(-1);
+	}
+
 	fprintf(stderr, "PASS\n");
 	exit(0);
 }