add missing checks to strlcpy() when copying envelope "destination" buffer

to the mda delivery buffer. we should never hit these unless we mistakenly
change the value of a define, better be safe than sorry.

(void) cast strlcpy/strlcat that cannot truncate or that we know and want
to truncate rather than lose (informative data not used by smtpd but
intended to help the human reading the log)

diff --git a/usr.sbin/smtpd/mda.c b/usr.sbin/smtpd/mda.c
index 44240e7..83a8e5a 100644 (file)
--- a/usr.sbin/smtpd/mda.c
+++ b/usr.sbin/smtpd/mda.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: mda.c,v 1.103 2014/04/04 16:10:42 eric Exp $  */
+/*     $OpenBSD: mda.c,v 1.104 2014/04/19 13:07:56 gilles Exp $        */
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@poolp.org>
@@ -264,9 +264,9 @@ mda_imsg(struct mproc *p, struct imsg *imsg)
                        case A_MDA:
                                deliver.mode = A_MDA;
                                deliver.userinfo = *userinfo;
-                               strlcpy(deliver.user, userinfo->username,
+                               (void)strlcpy(deliver.user, userinfo->username,
                                    sizeof(deliver.user));
-                               strlcpy(deliver.to, e->buffer,
+                               (void)strlcpy(deliver.to, e->buffer,
                                    sizeof(deliver.to));
                                break;
 
@@ -277,41 +277,74 @@ mda_imsg(struct mproc *p, struct imsg *imsg)
                                deliver.mode = A_MBOX;
                                deliver.userinfo = *userinfo;
                                deliver.userinfo.uid = 0;
-                               strlcpy(deliver.user, "root",
+                               (void)strlcpy(deliver.user, "root",
                                    sizeof(deliver.user));
-                               strlcpy(deliver.to, userinfo->username,
-                                   sizeof(deliver.to));
-                               strlcpy(deliver.from, e->sender,
+                               (void)strlcpy(deliver.from, e->sender,
                                    sizeof(deliver.from));
+                               (void)strlcpy(deliver.to, userinfo->username,
+                                   sizeof(deliver.to));
                                break;
 
                        case A_MAILDIR:
                                deliver.mode = A_MAILDIR;
                                deliver.userinfo = *userinfo;
-                               strlcpy(deliver.user, userinfo->username,
+                               (void)strlcpy(deliver.user, userinfo->username,
                                    sizeof(deliver.user));
-                               strlcpy(deliver.to, e->buffer,
-                                   sizeof(deliver.to));
+                               if (strlcpy(deliver.to, e->buffer,
+                                       sizeof(deliver.to))
+                                   >= sizeof(deliver.to)) {
+                                       log_warn("warn: mda: "
+                                           "deliver buffer too large");
+                                       mda_queue_tempfail(e->id,
+                                           "Maildir path too long",
+                                           ESC_OTHER_MAIL_SYSTEM_STATUS);
+                                       mda_log(e, "TempFail",
+                                           "Maildir path too long");
+                                       mda_done(s);
+                                       return;
+                               }
                                break;
 
                        case A_FILENAME:
                                deliver.mode = A_FILENAME;
                                deliver.userinfo = *userinfo;
-                               strlcpy(deliver.user, userinfo->username,
+                               (void)strlcpy(deliver.user, userinfo->username,
                                    sizeof deliver.user);
-                               strlcpy(deliver.to, e->buffer,
-                                   sizeof deliver.to);
+                               if (strlcpy(deliver.to, e->buffer,
+                                       sizeof(deliver.to))
+                                   >= sizeof(deliver.to)) {
+                                       log_warn("warn: mda: "
+                                           "deliver buffer too large");
+                                       mda_queue_tempfail(e->id,
+                                           "filename path too long",
+                                           ESC_OTHER_MAIL_SYSTEM_STATUS);
+                                       mda_log(e, "TempFail",
+                                           "filename path too long");
+                                       mda_done(s);
+                                       return;
+                               }
                                break;
 
                        case A_LMTP:
                                deliver.mode = A_LMTP;
                                deliver.userinfo = *userinfo;
-                               strlcpy(deliver.user, userinfo->username,
+                               (void)strlcpy(deliver.user, userinfo->username,
                                    sizeof(deliver.user));
-                               strlcpy(deliver.to, e->buffer,
-                                   sizeof(deliver.to));
-                               strlcpy(deliver.from, e->sender,
+                               (void)strlcpy(deliver.from, e->sender,
                                    sizeof(deliver.from));
+                               if (strlcpy(deliver.to, e->buffer,
+                                       sizeof(deliver.to))
+                                   >= sizeof(deliver.to)) {
+                                       log_warn("warn: mda: "
+                                           "deliver buffer too large");
+                                       mda_queue_tempfail(e->id,
+                                           "socket path too long",
+                                           ESC_OTHER_MAIL_SYSTEM_STATUS);
+                                       mda_log(e, "TempFail",
+                                           "socket path too long");
+                                       mda_done(s);
+                                       return;
+                               }
                                break;
 
                        default:
@@ -578,9 +611,9 @@ mda_getlastline(int fd, char *dst, size_t dstsz)
        fclose(fp);
 
        if (buf[0]) {
-               strlcpy(dst, "\"", dstsz);
-               strnvis(dst + 1, buf, dstsz - 2, VIS_SAFE | VIS_CSTYLE);
-               strlcat(dst, "\"", dstsz);
+               (void)strlcpy(dst, "\"", dstsz);
+               (void)strnvis(dst + 1, buf, dstsz - 2, VIS_SAFE | VIS_CSTYLE);
+               (void)strlcat(dst, "\"", dstsz);
        }
 
        return (0);
@@ -783,8 +816,8 @@ mda_user(const struct envelope *evp)
        u = xcalloc(1, sizeof *u, "mda_user");
        u->id = generate_uid();
        TAILQ_INIT(&u->envelopes);
-       strlcpy(u->name, evp->agent.mda.username, sizeof(u->name));
-       strlcpy(u->usertable, evp->agent.mda.usertable,
+       (void)strlcpy(u->name, evp->agent.mda.username, sizeof(u->name));
+       (void)strlcpy(u->usertable, evp->agent.mda.usertable,
            sizeof(u->usertable));
 
        tree_xset(&users, u->id, u);