fusermount: Check for argv[0] being present (#577)

It is perfectly legal to execute a program with argc == 0 and therefore
no argv.
fusermount needs to check for this case, otherwise it will pass a NULL
poiunter to strdup() and cause undefined behavior.
Especially since fusermount is setuid root, we need to extra be careful.

Signed-off-by: Richard Weinberger <richard@nod.at>

diff --git a/util/fusermount.c b/util/fusermount.c
index 45e96bce23115df13febaa80ac1df35af85c56fb..243d25ec5fabf79f733f5c82f5b24cb867799aba 100644 (file)
--- a/util/fusermount.c
+++ b/util/fusermount.c
@@ -1270,7 +1270,7 @@ int main(int argc, char *argv[])
                {"version", no_argument, NULL, 'V'},
                {0, 0, 0, 0}};
 
-       progname = strdup(argv[0]);
+       progname = strdup(argc > 0 ? argv[0] : "fusermount");
        if (progname == NULL) {
                fprintf(stderr, "%s: failed to allocate memory\n", argv[0]);
                exit(1);