[SA-14:25] Fix kernel stack disclosure in setlogin(2) / getlogin(2).

[SA-14:26] Fix remote command execution in ftp(1).

Approved by:	so (des)

2 files changed, 38 insertions, 29 deletions

diff --git a/contrib/tnftp/src/fetch.c b/contrib/tnftp/src/fetch.c
index 91b49fd..72153a5 100644
--- a/contrib/tnftp/src/fetch.c
+++ b/contrib/tnftp/src/fetch.c
@@ -547,7 +547,7 @@ fetch_url(const char *url, const char *proxyenv, char *proxyauth, char *wwwauth)
 	url_decode(decodedpath);
 
 	if (outfile)
-		savefile = ftp_strdup(outfile);
+		savefile = outfile;
 	else {
 		cp = strrchr(decodedpath, '/');		/* find savefile */
 		if (cp != NULL)
@@ -571,8 +571,7 @@ fetch_url(const char *url, const char *proxyenv, char *proxyauth, char *wwwauth)
 	rangestart = rangeend = entitylen = -1;
 	mtime = -1;
 	if (restartautofetch) {
-		if (strcmp(savefile, "-") != 0 && *savefile != '|' &&
-		    stat(savefile, &sb) == 0)
+		if (stat(savefile, &sb) == 0)
 			restart_point = sb.st_size;
 	}
 	if (urltype == FILE_URL_T) {		/* file:// URLs */
@@ -1098,17 +1097,25 @@ fetch_url(const char *url, const char *proxyenv, char *proxyauth, char *wwwauth)
 	}		/* end of ftp:// or http:// specific setup */
 
 			/* Open the output file. */
-	if (strcmp(savefile, "-") == 0) {
-		fout = stdout;
-	} else if (*savefile == '|') {
-		oldintp = xsignal(SIGPIPE, SIG_IGN);
-		fout = popen(savefile + 1, "w");
-		if (fout == NULL) {
-			warn("Can't execute `%s'", savefile + 1);
-			goto cleanup_fetch_url;
+
+	/*
+	 * Only trust filenames with special meaning if they came from
+	 * the command line
+	 */
+	if (outfile == savefile) {
+		if (strcmp(savefile, "-") == 0) {
+			fout = stdout;
+		} else if (*savefile == '|') {
+			oldintp = xsignal(SIGPIPE, SIG_IGN);
+			fout = popen(savefile + 1, "w");
+			if (fout == NULL) {
+				warn("Can't execute `%s'", savefile + 1);
+				goto cleanup_fetch_url;
+			}
+			closefunc = pclose;
 		}
-		closefunc = pclose;
-	} else {
+	}
+	if (fout == NULL) {
 		if ((rangeend != -1 && rangeend <= restart_point) ||
 		    (rangestart == -1 && filesize != -1 && filesize <= restart_point)) {
 			/* already done */
@@ -1318,7 +1325,8 @@ fetch_url(const char *url, const char *proxyenv, char *proxyauth, char *wwwauth)
 		(*closefunc)(fout);
 	if (res0)
 		freeaddrinfo(res0);
-	FREEPTR(savefile);
+	if (savefile != outfile)
+		FREEPTR(savefile);
 	FREEPTR(uuser);
 	if (pass != NULL)
 		memset(pass, 0, strlen(pass));
diff --git a/sys/kern/kern_prot.c b/sys/kern/kern_prot.c
index f99e053..9f7325c0 100644
--- a/sys/kern/kern_prot.c
+++ b/sys/kern/kern_prot.c
@@ -2073,21 +2073,20 @@ struct getlogin_args {
 int
 sys_getlogin(struct thread *td, struct getlogin_args *uap)
 {
-	int error;
 	char login[MAXLOGNAME];
 	struct proc *p = td->td_proc;
+	size_t len;
 
 	if (uap->namelen > MAXLOGNAME)
 		uap->namelen = MAXLOGNAME;
 	PROC_LOCK(p);
 	SESS_LOCK(p->p_session);
-	bcopy(p->p_session->s_login, login, uap->namelen);
+	len = strlcpy(login, p->p_session->s_login, uap->namelen) + 1;
 	SESS_UNLOCK(p->p_session);
 	PROC_UNLOCK(p);
-	if (strlen(login) + 1 > uap->namelen)
+	if (len > uap->namelen)
 		return (ERANGE);
-	error = copyout(login, uap->namebuf, uap->namelen);
-	return (error);
+	return (copyout(login, uap->namebuf, len));
 }
 
 /*
@@ -2106,21 +2105,23 @@ sys_setlogin(struct thread *td, struct setlogin_args *uap)
 	int error;
 	char logintmp[MAXLOGNAME];
 
+	CTASSERT(sizeof(p->p_session->s_login) >= sizeof(logintmp));
+
 	error = priv_check(td, PRIV_PROC_SETLOGIN);
 	if (error)
 		return (error);
 	error = copyinstr(uap->namebuf, logintmp, sizeof(logintmp), NULL);
-	if (error == ENAMETOOLONG)
-		error = EINVAL;
-	else if (!error) {
-		PROC_LOCK(p);
-		SESS_LOCK(p->p_session);
-		(void) memcpy(p->p_session->s_login, logintmp,
-		    sizeof(logintmp));
-		SESS_UNLOCK(p->p_session);
-		PROC_UNLOCK(p);
+	if (error != 0) {
+		if (error == ENAMETOOLONG)
+			error = EINVAL;
+		return (error);
 	}
-	return (error);
+	PROC_LOCK(p);
+	SESS_LOCK(p->p_session);
+	strcpy(p->p_session->s_login, logintmp);
+	SESS_UNLOCK(p->p_session);
+	PROC_UNLOCK(p);
+	return (0);
 }
 
 void