From: Dmitry V. Levin <ldv@altlinux.org>
Date: Sun, 2 Jul 2017 10:01:22 +0000 (+0000)
Subject: Fix error diagnostics in case of zero argc
X-Git-Tag: v4.18~8
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=373265e69957cad0240ccbadb7d17ff448ad581b;p=strace

Fix error diagnostics in case of zero argc

* strace.c (init): Adjust argc along with argv,
check that adjusted argc is sane.
* tests/zeroargc.c: New file.
* tests/.gitignore: Add zeroargc.
* tests/Makefile.am (check_PROGRAMS): Likewise.
* tests/options-syntax.test: Check strace error diagnostics
in case of zero argc.
---

diff --git a/strace.c b/strace.c
index 5ece0247..955a1c9f 100644
--- a/strace.c
+++ b/strace.c
@@ -1772,14 +1772,11 @@ init(int argc, char *argv[])
 			break;
 		}
 	}
-	argv += optind;
-	/* argc -= optind; - no need, argc is not used below */
 
-	acolumn_spaces = xmalloc(acolumn + 1);
-	memset(acolumn_spaces, ' ', acolumn);
-	acolumn_spaces[acolumn] = '\0';
+	argv += optind;
+	argc -= optind;
 
-	if (!argv[0] && !nprocs) {
+	if (argc < 0 || (!argv[0] && !nprocs)) {
 		error_msg_and_help("must have PROG [ARGS] or -p PID");
 	}
 
@@ -1821,6 +1818,10 @@ init(int argc, char *argv[])
 		tflag = 1;
 	}
 
+	acolumn_spaces = xmalloc(acolumn + 1);
+	memset(acolumn_spaces, ' ', acolumn);
+	acolumn_spaces[acolumn] = '\0';
+
 	sigprocmask(SIG_SETMASK, NULL, &start_set);
 	memcpy(&blocked_set, &start_set, sizeof(blocked_set));
 
diff --git a/tests/.gitignore b/tests/.gitignore
index cca763fc..62de90b5 100644
--- a/tests/.gitignore
+++ b/tests/.gitignore
@@ -413,3 +413,4 @@ xetitimer
 xetpgid
 xetpriority
 xettimeofday
+zeroargc
diff --git a/tests/Makefile.am b/tests/Makefile.am
index fd07b03c..19b7400f 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -136,6 +136,7 @@ check_PROGRAMS = $(PURE_EXECUTABLES) \
 	vfork-f \
 	wait4-v \
 	waitid-v \
+	zeroargc \
 	# end of check_PROGRAMS
 
 attach_f_p_LDADD = -lrt -lpthread $(LDADD)
diff --git a/tests/options-syntax.test b/tests/options-syntax.test
index c187956a..7cfc579b 100755
--- a/tests/options-syntax.test
+++ b/tests/options-syntax.test
@@ -130,6 +130,17 @@ check_h "invalid -s argument: '-42'" -s -42
 check_h "invalid -s argument: '1073741824'" -s 1073741824
 check_h "invalid -I argument: '5'" -I 5
 
+cat > "$EXP" << '__EOF__'
+strace: must have PROG [ARGS] or -p PID
+Try 'strace -h' for more information.
+__EOF__
+../zeroargc "$strace_exp" /bin/true 2> "$LOG" &&
+	dump_log_and_fail_with \
+		'zeroargc strace failed to handle the error properly'
+match_diff "$LOG" "$EXP" ||
+	dump_log_and_fail_with \
+		'zeroargc strace failed to print expected diagnostics'
+
 if [ -n "${UID-}" ]; then
 	if [ "${UID-}" = 0 ]; then
 		umsg="Cannot find user ':nosuchuser:'"
diff --git a/tests/zeroargc.c b/tests/zeroargc.c
new file mode 100644
index 00000000..05d47dc3
--- /dev/null
+++ b/tests/zeroargc.c
@@ -0,0 +1,43 @@
+/*
+ * Execute an executable with zero argc and specified anvironment.
+ *
+ * Copyright (c) 2017 Dmitry V. Levin <ldv@altlinux.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "tests.h"
+#include <stdlib.h>
+#include <unistd.h>
+
+int
+main(const int ac, char **const av)
+{
+	if (ac < 2)
+		error_msg_and_fail("missing operand");
+	const char *const path = av[1];
+	av[1] = 0;
+	execve(path, av + 1, av + 2);
+	perror_msg_and_fail("execve: %s", path);
+}