From e127449a989f358c6ebec79ab7469c69d6949129 Mon Sep 17 00:00:00 2001
From: Fredrik Fornwall <fredrik@fornwall.net>
Date: Thu, 28 Sep 2017 23:55:58 +0200
Subject: [PATCH] Check executable permission of file (#5)

---
 run-tests.sh                     | 2 +-
 termux-exec.c                    | 3 +++
 tests/not-executable.sh          | 3 +++
 tests/not-executable.sh-expected | 1 +
 4 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 tests/not-executable.sh
 create mode 100644 tests/not-executable.sh-expected

diff --git a/run-tests.sh b/run-tests.sh
index 6720343..0c831d7 100755
--- a/run-tests.sh
+++ b/run-tests.sh
@@ -9,7 +9,7 @@ for f in tests/*.sh; do
 	ACTUAL_FILE=$f-actual
 
 	rm -f $ACTUAL_FILE
-	$f myarg1 myarg2 > $ACTUAL_FILE
+	$f myarg1 myarg2 &> $ACTUAL_FILE
 
 	if cmp --silent $ACTUAL_FILE $EXPECTED_FILE; then
 		printf " OK\n"
diff --git a/termux-exec.c b/termux-exec.c
index 66e9622..51fcb22 100644
--- a/termux-exec.c
+++ b/termux-exec.c
@@ -26,6 +26,9 @@ int execve(const char* filename, char* const* argv, char *const envp[])
 	char filename_buffer[512];
 	filename = termux_rewrite_executable(filename, filename_buffer, sizeof(filename_buffer));
 
+	// Error out if the file is not executable:
+	if (access(filename, X_OK) != 0) goto final;
+
 	fd = open(filename, O_RDONLY);
 	if (fd == -1) goto final;
 
diff --git a/tests/not-executable.sh b/tests/not-executable.sh
new file mode 100644
index 0000000..2a22daa
--- /dev/null
+++ b/tests/not-executable.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+echo hello
diff --git a/tests/not-executable.sh-expected b/tests/not-executable.sh-expected
new file mode 100644
index 0000000..5e7557b
--- /dev/null
+++ b/tests/not-executable.sh-expected
@@ -0,0 +1 @@
+./run-tests.sh: line 12: tests/not-executable.sh: Permission denied