- (djm) [groupaccess.c uidswap.c] Bug #787: Size group arrays at runtime

   using sysconf() if available Based on patches from
   holger AT van-lengerich.de and openssh_bugzilla AT hockin.org

diff --git a/ChangeLog b/ChangeLog
index fcb31c8745ac0f9c6d0f82ecae0baa50c30b5110..97ce04d4379d3fd0b6e23d13967e7a98195e41cf 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -16,6 +16,9 @@
  - (dtucker) [configure.ac gss-serv-krb5.c ssh-gss.h] Define GSSAPI when found
    with krb5-config, hunt down gssapi.h and friends.  Based partially on patch
    from deengert at anl.gov.  ok djm@
+ - (djm) [groupaccess.c uidswap.c] Bug #787: Size group arrays at runtime 
+   using sysconf() if available Based on patches from 
+   holger AT van-lengerich.de and openssh_bugzilla AT hockin.org
 
 20040223
  - (dtucker) [session.c] Bug #789: Only make setcred call for !privsep in the

diff --git a/groupaccess.c b/groupaccess.c
index fbf794fc87b8405067a525e5c8c657587a441533..f50879f83a9fae7b0a72514b5d2cb72024cd7119 100644 (file)
--- a/groupaccess.c
+++ b/groupaccess.c
@@ -31,7 +31,7 @@ RCSID("$OpenBSD: groupaccess.c,v 1.6 2003/04/08 20:21:28 itojun Exp $");
 #include "log.h"
 
 static int ngroups;
-static char *groups_byname[NGROUPS_MAX + 1];   /* +1 for base/primary group */
+static char **groups_byname;
 
 /*
  * Initialize group access list for user with primary (base) and
@@ -40,19 +40,27 @@ static char *groups_byname[NGROUPS_MAX + 1];        /* +1 for base/primary group */
 int
 ga_init(const char *user, gid_t base)
 {
-       gid_t groups_bygid[NGROUPS_MAX + 1];
+       gid_t *groups_bygid;
        int i, j;
        struct group *gr;
 
        if (ngroups > 0)
                ga_free();
 
-       ngroups = sizeof(groups_bygid) / sizeof(gid_t);
+       ngroups = NGROUPS_MAX;
+#if defined(HAVE_SYSCONF) && defined(_SC_NGROUPS_MAX)
+       ngroups = MAX(NGROUPS_MAX, sysconf(_SC_NGROUPS_MAX));
+#endif
+
+       groups_bygid = xmalloc(ngroups * sizeof(*groups_bygid));
+       groups_byname = xmalloc(ngroups * sizeof(*groups_byname));
+
        if (getgrouplist(user, base, groups_bygid, &ngroups) == -1)
                logit("getgrouplist: groups list too small");
        for (i = 0, j = 0; i < ngroups; i++)
                if ((gr = getgrgid(groups_bygid[i])) != NULL)
                        groups_byname[j++] = xstrdup(gr->gr_name);
+       xfree(groups_bygid);
        return (ngroups = j);
 }
 
@@ -84,5 +92,6 @@ ga_free(void)
                for (i = 0; i < ngroups; i++)
                        xfree(groups_byname[i]);
                ngroups = 0;
+               xfree(groups_byname);
        }
 }

diff --git a/uidswap.c b/uidswap.c
index 4cabaa444d3a5bf2e67d11f85f1a30ecc2920b24..e652161af938e2c2a0e22ad73f7646b6cd27a60e 100644 (file)
--- a/uidswap.c
+++ b/uidswap.c
@@ -16,6 +16,7 @@ RCSID("$OpenBSD: uidswap.c,v 1.24 2003/05/29 16:58:45 deraadt Exp $");
 
 #include "log.h"
 #include "uidswap.h"
+#include "xmalloc.h"
 
 /*
  * Note: all these functions must work in all of the following cases:
@@ -38,7 +39,7 @@ static gid_t  saved_egid = 0;
 /* Saved effective uid. */
 static int     privileged = 0;
 static int     temporarily_use_uid_effective = 0;
-static gid_t   saved_egroups[NGROUPS_MAX], user_groups[NGROUPS_MAX];
+static gid_t   *saved_egroups = NULL, *user_groups = NULL;
 static int     saved_egroupslen = -1, user_groupslen = -1;
 
 /*
@@ -68,18 +69,38 @@ temporarily_use_uid(struct passwd *pw)
 
        privileged = 1;
        temporarily_use_uid_effective = 1;
-       saved_egroupslen = getgroups(NGROUPS_MAX, saved_egroups);
+
+       saved_egroupslen = getgroups(0, NULL);
        if (saved_egroupslen < 0)
                fatal("getgroups: %.100s", strerror(errno));
+       if (saved_egroupslen > 0) {
+               saved_egroups = xrealloc(saved_egroups,
+                   saved_egroupslen * sizeof(gid_t));
+               if (getgroups(saved_egroupslen, saved_egroups) < 0)
+                       fatal("getgroups: %.100s", strerror(errno));
+       } else { /* saved_egroupslen == 0 */
+               if (saved_egroups)
+                       xfree(saved_egroups);
+       }
 
        /* set and save the user's groups */
        if (user_groupslen == -1) {
                if (initgroups(pw->pw_name, pw->pw_gid) < 0)
                        fatal("initgroups: %s: %.100s", pw->pw_name,
                            strerror(errno));
-               user_groupslen = getgroups(NGROUPS_MAX, user_groups);
+
+               user_groupslen = getgroups(0, NULL);
                if (user_groupslen < 0)
                        fatal("getgroups: %.100s", strerror(errno));
+               if (user_groupslen > 0) {
+                       user_groups = xrealloc(user_groups,
+                           user_groupslen * sizeof(gid_t));
+                       if (getgroups(user_groupslen, user_groups) < 0)
+                               fatal("getgroups: %.100s", strerror(errno));
+               } else { /* user_groupslen == 0 */
+                       if (user_groups)
+                               xfree(user_groups);
+               }
        }
        /* Set the effective uid to the given (unprivileged) uid. */
        if (setgroups(user_groupslen, user_groups) < 0)