lib/mangle: check for end of string on every iteration

Checking for the null byte at the end of the string only conditionally
leads to segfaults, evidenced by mount helpers crashing on writes to
/run/mount/utab. Simply check for the null on each iteration, and append
a null byte to the mangled string before breaking.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>

diff --git a/lib/mangle.c b/lib/mangle.c
index e1b48149f9731a75c926579a7b17ad1dda49b1a2..656918c4bbbe4da3ec1724d70ee4aeae414749eb 100644 (file)
--- a/lib/mangle.c
+++ b/lib/mangle.c
@@ -31,16 +31,17 @@ char *mangle(const char *s)
        if (!sp)
                return NULL;
        while(1) {
+               if (!*s) {
+                       *sp = '\0';
+                       break;
+               }
                if (is_unwanted_char(*s)) {
                        *sp++ = '\\';
                        *sp++ = '0' + ((*s & 0300) >> 6);
                        *sp++ = '0' + ((*s & 070) >> 3);
                        *sp++ = '0' + (*s & 07);
-               } else {
+               } else
                        *sp++ = *s;
-                       if (!*s)
-                               break;
-               }
                s++;
        }
        return ss;