upstream: invalidate supplemental group cache used by

temporarily_use_uid() when the target uid differs; could cause failure to
read authorized_keys under some configurations. patch by Jakub Jelen via
bz2873; ok dtucker, markus

OpenBSD-Commit-ID: 48a345f0ee90f6c465a078eb5e89566b23abd8a1
This commit is contained in:
djm@openbsd.org 2018-06-15 07:01:11 +00:00 committed by Damien Miller
parent 89a85d7247
commit 26f96ca10a
1 changed files with 6 additions and 2 deletions

View File

@ -1,4 +1,4 @@
/* $OpenBSD: uidswap.c,v 1.39 2015/06/24 01:49:19 dtucker Exp $ */
/* $OpenBSD: uidswap.c,v 1.40 2018/06/15 07:01:11 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -49,6 +49,7 @@ static gid_t saved_egid = 0;
/* Saved effective uid. */
static int privileged = 0;
static int temporarily_use_uid_effective = 0;
static uid_t user_groups_uid;
static gid_t *saved_egroups = NULL, *user_groups = NULL;
static int saved_egroupslen = -1, user_groupslen = -1;
@ -92,10 +93,11 @@ temporarily_use_uid(struct passwd *pw)
fatal("getgroups: %.100s", strerror(errno));
} else { /* saved_egroupslen == 0 */
free(saved_egroups);
saved_egroups = NULL;
}
/* set and save the user's groups */
if (user_groupslen == -1) {
if (user_groupslen == -1 || user_groups_uid != pw->pw_uid) {
if (initgroups(pw->pw_name, pw->pw_gid) < 0)
fatal("initgroups: %s: %.100s", pw->pw_name,
strerror(errno));
@ -110,7 +112,9 @@ temporarily_use_uid(struct passwd *pw)
fatal("getgroups: %.100s", strerror(errno));
} else { /* user_groupslen == 0 */
free(user_groups);
user_groups = NULL;
}
user_groups_uid = pw->pw_uid;
}
/* Set the effective uid to the given (unprivileged) uid. */
if (setgroups(user_groupslen, user_groups) < 0)