diff --git a/libmisc/sub.c b/libmisc/sub.c index d30c4c76..821596d1 100644 --- a/libmisc/sub.c +++ b/libmisc/sub.c @@ -15,8 +15,10 @@ #include #include "prototypes.h" #include "defines.h" +#define MAX_SUBROOT2 "maximum subsystem depth reached\n" #define BAD_SUBROOT2 "invalid root `%s' for user `%s'\n" #define NO_SUBROOT2 "no subsystem root `%s' for user `%s'\n" +#define MAX_DEPTH 1024 /* * subsystem - change to subsystem root * @@ -27,6 +29,18 @@ */ void subsystem (const struct passwd *pw) { + static int depth = 0; + + /* + * Prevent endless loop on misconfigured systems. + */ + if (++depth > MAX_DEPTH) { + printf (_("Maximum subsystem depth reached\n")); + SYSLOG ((LOG_WARN, MAX_SUBROOT2)); + closelog (); + exit (EXIT_FAILURE); + } + /* * The new root directory must begin with a "/" character. */