sssd/0012-krb5-Add-file-dir-path-precheck.patch
Jakub Hrozek 8d72fcd900 Backport simplification of ccache management from 1.11.1
- Resolves: rhbz#1010553 - sssd setting KRB5CCNAME=(null) on login
2013-09-23 14:45:29 +02:00

98 lines
3.5 KiB
Diff

From 14050f35224360883e20ebd810d3eb40f39267cf Mon Sep 17 00:00:00 2001
From: Simo Sorce <simo@redhat.com>
Date: Sat, 31 Aug 2013 14:21:22 -0400
Subject: [PATCH 12/14] krb5: Add file/dir path precheck
Add a precheck on the actual existence at all of the file/dir ccname
targeted (for FILE/DIR types), and bail early if nothing is available.
While testing I found out that without this check, the krb5_cc_resolve()
function we call as user to check old paths would try to create the
directory if it didn't exist.
With a ccname of DIR:/tmp/ccdir_1000 saved in the user entry this would
cause two undesirable side effects:
First it would actually create a directory with the old name, when it
should not.
Second, because for some reason the umask is set to 0127 in sssd_be, it
would create the directory with permission 600 (missing the 'x' traverse
bit on the directory. If the new ccache has the same name it would cause
the krb5_child process to fal to store the credential cache in it.
Related:
https://fedorahosted.org/sssd/ticket/2061
---
src/providers/krb5/krb5_auth.c | 1 +
src/providers/krb5/krb5_utils.c | 34 ++++++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)
diff --git a/src/providers/krb5/krb5_auth.c b/src/providers/krb5/krb5_auth.c
index 1585f709655853827f2778010452a58657add5d0..7cfa3e943c15c0f515f3372079cee18dd7978c92 100644
--- a/src/providers/krb5/krb5_auth.c
+++ b/src/providers/krb5/krb5_auth.c
@@ -69,6 +69,7 @@ check_old_ccache(const char *old_ccache, struct krb5child_req *kr,
realm, kr->upn);
switch (ret) {
case ERR_NOT_FOUND:
+ case ENOENT:
DEBUG(SSSDBG_TRACE_FUNC,
("Saved ccache %s doesn't exist.\n", old_ccache));
return ENOENT;
diff --git a/src/providers/krb5/krb5_utils.c b/src/providers/krb5/krb5_utils.c
index d0ccd2d7e03bcabe07113b5abb43d9119b35321c..bb933d7f722cbef90b73f4a721382165572c69b9 100644
--- a/src/providers/krb5/krb5_utils.c
+++ b/src/providers/krb5/krb5_utils.c
@@ -967,6 +967,30 @@ done:
return ret;
}
+static errno_t sss_low_level_path_check(const char *ccname)
+{
+ const char *filename;
+ struct stat buf;
+ int ret;
+
+ if (ccname[0] == '/') {
+ filename = ccname;
+ } else if (strncmp(ccname, "FILE:", 5) == 0) {
+ filename = ccname + 5;
+ } else if (strncmp(ccname, "DIR:", 4) == 0) {
+ filename = ccname + 4;
+ if (filename[0] == ':') filename += 1;
+ } else {
+ /* only FILE and DIR types need file checks so far, we ignore any
+ * other type */
+ return EOK;
+ }
+
+ ret = stat(filename, &buf);
+ if (ret == -1) return errno;
+ return EOK;
+}
+
errno_t sss_krb5_cc_verify_ccache(const char *ccname, uid_t uid, gid_t gid,
const char *realm, const char *principal)
{
@@ -980,6 +1004,16 @@ errno_t sss_krb5_cc_verify_ccache(const char *ccname, uid_t uid, gid_t gid,
krb5_error_code kerr;
errno_t ret;
+ /* first of all verify if the old ccache file/dir exists as we may be
+ * trying to verify if an old ccache exists at all. If no file/dir
+ * exists bail out immediately otherwise a following krb5_cc_resolve()
+ * call may actually create paths and files we do not want to have
+ * around */
+ ret = sss_low_level_path_check(ccname);
+ if (ret) {
+ return ret;
+ }
+
tmp_ctx = talloc_new(NULL);
if (tmp_ctx == NULL) {
DEBUG(SSSDBG_CRIT_FAILURE, ("talloc_new failed.\n"));
--
1.8.3.1