Use reentrant versions of getpw{nam,uid} and getgr{nam,gid} within

libc to avoid reusing the static buffers returned by the non-reentrant
versions.  Since this is inside libc we can use constants for the
buffer sizes instead of having to call sysconf().
OK guenther@ deraadt@

2 files changed, 10 insertions, 7 deletions

diff --git a/src/lib/libc/net/rcmdsh.c b/src/lib/libc/net/rcmdsh.c
index 5d468ff4c4..14275d414a 100644
--- a/src/lib/libc/net/rcmdsh.c
+++ b/src/lib/libc/net/rcmdsh.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: rcmdsh.c,v 1.17 2015/11/01 03:45:29 guenther Exp $    */ 
+/*      $OpenBSD: rcmdsh.c,v 1.18 2015/11/24 22:03:33 millert Exp $     */ 
 
 /*
  * Copyright (c) 2001, MagniComp
@@ -58,15 +58,16 @@ rcmdsh(char **ahost, int rport, const char *locuser, const char *remuser,
         struct hostent *hp;
         int sp[2];
         pid_t cpid;
-        char *p;
-        struct passwd *pw;
+        char *p, pwbuf[_PW_BUF_LEN];
+        struct passwd pwstore, *pw = NULL;
 
         /* What rsh/shell to use. */
         if (rshprog == NULL)
                 rshprog = _PATH_RSH;
 
         /* locuser must exist on this host. */
-        if ((pw = getpwnam(locuser)) == NULL) {
+        getpwnam_r(locuser, &pwstore, pwbuf, sizeof(pwbuf), &pw);
+        if (pw == NULL) {
                 (void) fprintf(stderr, "rcmdsh: unknown user: %s\n", locuser);
                 return(-1);
         }
diff --git a/src/lib/libc/net/ruserok.c b/src/lib/libc/net/ruserok.c
index 88c89ac40f..7dda9550a8 100644
--- a/src/lib/libc/net/ruserok.c
+++ b/src/lib/libc/net/ruserok.c
@@ -111,11 +111,11 @@ iruserok_sa(const void *raddr, int rlen, int superuser, const char *ruser,
         struct sockaddr *sa;
         char *cp;
         struct stat sbuf;
-        struct passwd *pwd;
+        struct passwd pwstore, *pwd;
         FILE *hostf;
         uid_t uid;
         int first;
-        char pbuf[PATH_MAX];
+        char pbuf[PATH_MAX], pwbuf[_PW_BUF_LEN];
 
         sa = (struct sockaddr *)raddr;
         first = 1;
@@ -132,7 +132,9 @@ again:
                 int len;
 
                 first = 0;
-                if ((pwd = getpwnam(luser)) == NULL)
+                pwd = NULL;
+                getpwnam_r(luser, &pwstore, pwbuf, sizeof(pwbuf), &pwd);
+                if (pwd == NULL)
                         return (-1);
                 len = snprintf(pbuf, sizeof pbuf, "%s/.rhosts", pwd->pw_dir);
                 if (len < 0 || len >= sizeof pbuf)