masqmail
diff src/masqmail.c @ 331:e507c854a63e
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 16:19:07 +0200 |
| parents | f10a56dc7481 |
| children | b45dc53f2829 |
line diff
1.1 --- a/src/masqmail.c Wed Jul 13 10:30:52 2011 +0200 1.2 +++ b/src/masqmail.c Sat Aug 27 16:19:07 2011 +0200 1.3 @@ -61,8 +61,10 @@ 1.4 sigterm_in_progress = 1; 1.5 1.6 if (pidfile) { 1.7 - uid_t uid; 1.8 - uid = seteuid(0); 1.9 + uid_t uid = geteuid(); 1.10 + if (seteuid(0) != 0) { 1.11 + logwrite(LOG_ALERT, "sigterm_handler: could not set euid to %d: %s\n", 0, strerror(errno)); 1.12 + } 1.13 if (unlink(pidfile) != 0) 1.14 logwrite(LOG_WARNING, "could not delete pid file %s: %s\n", pidfile, strerror(errno)); 1.15 seteuid(uid); /* we exit anyway after this, just to be sure */ 1.16 @@ -187,8 +189,7 @@ 1.17 conf.do_verbose = FALSE; 1.18 1.19 if (!conf.run_as_user) { 1.20 - seteuid(conf.orig_uid); 1.21 - setegid(conf.orig_gid); 1.22 + set_euidgid(conf.orig_uid, conf.orig_gid, NULL, NULL); 1.23 } 1.24 1.25 DEBUG(5) debugf("accepting smtp message on stdin\n"); 1.26 @@ -217,8 +218,7 @@ 1.27 } 1.28 1.29 if (!conf.run_as_user) { 1.30 - seteuid(conf.orig_uid); 1.31 - setegid(conf.orig_gid); 1.32 + set_euidgid(conf.orig_uid, conf.orig_gid, NULL, NULL); 1.33 } 1.34 1.35 DEBUG(5) debugf("accepting message on stdin\n"); 1.36 @@ -647,10 +647,15 @@ 1.37 */ 1.38 if ((strcmp(conf_file, CONF_FILE) != 0) && (conf.orig_uid != 0)) { 1.39 conf.run_as_user = TRUE; 1.40 - seteuid(conf.orig_uid); 1.41 - setegid(conf.orig_gid); 1.42 - setuid(conf.orig_uid); 1.43 - setgid(conf.orig_gid); 1.44 + set_euidgid(conf.orig_uid, conf.orig_gid, NULL, NULL); 1.45 + if (setgid(conf.orig_gid)) { 1.46 + logwrite(LOG_ALERT, "could not set gid to %d: %s\n", conf.orig_gid, strerror(errno)); 1.47 + exit(1); 1.48 + } 1.49 + if (setuid(conf.orig_uid)) { 1.50 + logwrite(LOG_ALERT, "could not set uid to %d: %s\n", conf.orig_uid, strerror(errno)); 1.51 + exit(1); 1.52 + } 1.53 } 1.54 1.55 conf.log_dir = LOG_DIR;