diff options
| -rw-r--r-- | Config.in | 8 | ||||
| -rw-r--r-- | lib/lib.c | 10 | ||||
| -rw-r--r-- | lib/lib.h | 1 | ||||
| -rw-r--r-- | main.c | 15 | ||||
| -rw-r--r-- | toys.h | 5 |
5 files changed, 39 insertions, 0 deletions
@@ -11,6 +11,14 @@ config TOYBOX With no arguments, shows available commands. First argument is name of a command to run, followed by any arguments to that command. +config TOYBOX_SUID + bool "SUID support" + default y + help + Support for suid commands, which run as root. This means toybox must + be installed suid root, and drops permissions before running commands + which do not require root access. + config TOYBOX_FREE bool "Free memory unnecessarily" default n @@ -369,6 +369,16 @@ void xmkpath(char *path, int mode) if (!*p) break; } } + +// setuid() can fail (for example, too many processes belonging to that user), +// which opens a security hole if the process continues as the original user. + +void xsetuid(uid_t uid) +{ + if (setuid(uid)) perror_exit("xsetuid"); +} + + // Find all file in a colon-separated path with access type "type" (generally // X_OK or R_OK). Returns a list of absolute paths to each file found, in // order. @@ -81,6 +81,7 @@ void xstat(char *path, struct stat *st); char *xabspath(char *path); void xchdir(char *path); void xmkpath(char *path, int mode); +void xsetuid(uid_t uid); struct string_list *find_in_path(char *path, char *filename); void utoa_to_buf(unsigned n, char *buf, unsigned buflen); void itoa_to_buf(int n, char *buf, unsigned buflen); @@ -64,6 +64,21 @@ static const int NEED_OPTIONS = void toy_init(struct toy_list *which, char *argv[]) { + // Drop permissions for non-suid commands. + + if (CFG_TOYBOX_SUID) { + uid_t uid = getuid(), euid = geteuid(); + + if (!(which->flags & TOYFLAG_STAYROOT)) { + if (uid != euid) xsetuid(euid=uid); + } else if (CFG_TOYBOX_DEBUG && uid) + error_exit("Not installed suid root"); + + if ((which->flags & TOYFLAG_NEEDROOT) && euid) + error_exit("Not root"); + + } + // Free old toys contents here? toys.which = which; @@ -68,6 +68,11 @@ void toy_exec(char *argv[]); // Start applet with a umask of 0 (saves old umask in this.old_umask) #define TOYFLAG_UMASK (1<<5) +// This applet runs as root. +#define TOYFLAG_STAYROOT (1<<6) +#define TOYFLAG_NEEDROOT (1<<7) +#define TOYFLAG_ROOTONLY (TOYFLAG_STAYROOT|TOYFLAG_NEEDROOT) + // Array of available applets extern struct toy_list { |