Mercurial > masqmail-0.2
diff src/masqmail.c @ 184:b3835b6b834b
Security fix! Correct handling of seteuid() return value
See Debian bug #638002, reported by John Lightsey.
When possible the (already available) set_euidgid() function is used.
Additionally, it is unnecessary to change the identity when writing
into an already open file descriptor.
This should fix the problem.
| author | markus schnalke <meillo@marmaro.de> |
|---|---|
| date | Sat, 27 Aug 2011 18:00:40 +0200 |
| parents | 2ac8a66ee108 |
| children |
line wrap: on
line diff
--- a/src/masqmail.c Fri Jun 03 13:32:14 2011 +0200 +++ b/src/masqmail.c Sat Aug 27 18:00:40 2011 +0200 @@ -62,8 +62,10 @@ sigterm_in_progress = 1; if (pidfile) { - uid_t uid; - uid = seteuid(0); + uid_t uid = geteuid(); + if (seteuid(0) != 0) { + logwrite(LOG_ALERT, "sigterm_handler: could not set euid to %d: %s\n", 0, strerror(errno)); + } if (unlink(pidfile) != 0) logwrite(LOG_WARNING, "could not delete pid file %s: %s\n", pidfile, strerror(errno)); seteuid(uid); /* we exit anyway after this, just to be sure */ @@ -236,8 +238,7 @@ conf.do_verbose = FALSE; if (!conf.run_as_user) { - seteuid(conf.orig_uid); - setegid(conf.orig_gid); + set_euidgid(conf.orig_uid, conf.orig_gid, NULL, NULL); } DEBUG(5) debugf("accepting smtp message on stdin\n"); @@ -265,8 +266,7 @@ } if (!conf.run_as_user) { - seteuid(conf.orig_uid); - setegid(conf.orig_gid); + set_euidgid(conf.orig_uid, conf.orig_gid, NULL, NULL); } DEBUG(5) debugf("accepting message on stdin\n"); @@ -632,13 +632,16 @@ So it is possible for a user to run his own daemon without breaking security. */ - if (strcmp(conf_file, CONF_FILE) != 0) { - if (conf.orig_uid != 0) { - conf.run_as_user = TRUE; - seteuid(conf.orig_uid); - setegid(conf.orig_gid); - setuid(conf.orig_uid); - setgid(conf.orig_gid); + if ((strcmp(conf_file, CONF_FILE) != 0) && (conf.orig_uid != 0)) { + conf.run_as_user = TRUE; + set_euidgid(conf.orig_uid, conf.orig_gid, NULL, NULL); + if (setgid(conf.orig_gid)) { + logwrite(LOG_ALERT, "could not set gid to %d: %s\n", conf.orig_gid, strerror(errno)); + exit(1); + } + if (setuid(conf.orig_uid)) { + logwrite(LOG_ALERT, "could not set uid to %d: %s\n", conf.orig_uid, strerror(errno)); + exit(1); } }