Avoid potential NULL dereference when argv[0]

Addresses-Coverity-Bug: 1500772
Addresses-Coverity-Bug: 1500769
Addresses-Coverity-Bug: 1500767
Addresses-Coverity-Bug: 1500758
Addresses-Coverity-Bug: 1500756
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

7 files changed, 19 insertions, 4 deletions

diff --git a/e2fsck/unix.c b/e2fsck/unix.c
index 3708a4d80..4b6fd0999 100644
--- a/e2fsck/unix.c
+++ b/e2fsck/unix.c
@@ -74,11 +74,15 @@ int journal_enable_debug = -1;
 
 static void usage(e2fsck_t ctx)
 {
+	char *program_name = "e2fsck";
+
+	if (ctx && ctx->program_name)
+		program_name = ctx>program_name;
 	fprintf(stderr,
 		_("Usage: %s [-panyrcdfktvDFV] [-b superblock] [-B blocksize]\n"
 		"\t\t[-l|-L bad_blocks_file] [-C fd] [-j external_journal]\n"
 		"\t\t[-E extended-options] [-z undo_file] device\n"),
-		ctx->program_name);
+		program_name);
 
 	fprintf(stderr, "%s", _("\nEmergency help:\n"
 		" -p                   Automatic repair (no questions)\n"
@@ -849,7 +853,7 @@ static errcode_t PRS(int argc, char *argv[], e2fsck_t *ret_ctx)
 	if (argc && *argv)
 		ctx->program_name = *argv;
 	else
-		ctx->program_name = "e2fsck";
+		usage(NULL);
 
 	phys_mem_kb = get_memory_size() / 1024;
 	ctx->readahead_kb = ~0ULL;
diff --git a/misc/badblocks.c b/misc/badblocks.c
index afeb3da9d..3dedf7630 100644
--- a/misc/badblocks.c
+++ b/misc/badblocks.c
@@ -1093,6 +1093,8 @@ int main (int argc, char ** argv)
 
 	if (argc && *argv)
 		program_name = *argv;
+	else
+		usage();
 	while ((c = getopt (argc, argv, "b:d:e:fi:o:svwnc:p:h:t:BX")) != EOF) {
 		switch (c) {
 		case 'b':
diff --git a/misc/dumpe2fs.c b/misc/dumpe2fs.c
index ef6d1cb82..7c080ed9f 100644
--- a/misc/dumpe2fs.c
+++ b/misc/dumpe2fs.c
@@ -619,7 +619,8 @@ int main (int argc, char ** argv)
 			mmp_check = 1;
 			header_only = 1;
 		}
-	}
+	} else
+		usage();
 
 	if (!mmp_check)
 		fprintf(stderr, "dumpe2fs %s (%s)\n", E2FSPROGS_VERSION,
diff --git a/misc/e2image.c b/misc/e2image.c
index 207c30374..f9357aa0c 100644
--- a/misc/e2image.c
+++ b/misc/e2image.c
@@ -1517,6 +1517,8 @@ int main (int argc, char ** argv)
 		 E2FSPROGS_DATE);
 	if (argc && *argv)
 		program_name = *argv;
+	else
+		usage();
 	add_error_table(&et_ext2_error_table);
 	while ((c = getopt(argc, argv, "b:B:nrsIQafo:O:pc")) != EOF)
 		switch (c) {
diff --git a/misc/lsattr.c b/misc/lsattr.c
index 55080e92a..72f4c6816 100644
--- a/misc/lsattr.c
+++ b/misc/lsattr.c
@@ -187,6 +187,8 @@ int main (int argc, char ** argv)
 #endif
 	if (argc && *argv)
 		program_name = *argv;
+	else
+		usage();
 	while ((c = getopt (argc, argv, "RVadlvp")) != EOF)
 		switch (c)
 		{
diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index 7f023adfa..64a456af3 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -2951,6 +2951,8 @@ int tune2fs_main(int argc, char **argv)
 #endif
 	if (argc && *argv)
 		program_name = *argv;
+	else
+		usage();
 	add_error_table(&et_ext2_error_table);
 
 #ifdef CONFIG_BUILD_FINDFS
diff --git a/resize/main.c b/resize/main.c
index b745c58c2..94f5ec6d6 100644
--- a/resize/main.c
+++ b/resize/main.c
@@ -49,7 +49,7 @@ static void usage (char *prog)
 	fprintf (stderr, _("Usage: %s [-d debug_flags] [-f] [-F] [-M] [-P] "
 			   "[-p] device [-b|-s|new_size] [-S RAID-stride] "
 			   "[-z undo_file]\n\n"),
-		 prog);
+		 prog ? prog : "resize2fs");
 
 	exit (1);
 }
@@ -287,6 +287,8 @@ int main (int argc, char ** argv)
 		 E2FSPROGS_VERSION, E2FSPROGS_DATE);
 	if (argc && *argv)
 		program_name = *argv;
+	else
+		usage(NULL);
 
 	while ((c = getopt(argc, argv, "d:fFhMPpS:bsz:")) != EOF) {
 		switch (c) {