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From 8d14ff153e9335b09739438344f9c3c78a496548 Mon Sep 17 00:00:00 2001
From: Mark Reynolds <mreynolds@redhat.com>
Date: Fri, 22 May 2020 10:42:11 -0400
Subject: [PATCH 08/12] Issue 51095 - abort operation if CSN can not be
 generated

Bug Description:  If we fail to get the system time then we were using an
                  uninitialized timespec struct which could lead to bizarre
                  times in CSN's.

Fix description:  Check if the system time function fails, and if it does
                  then abort the update operation.

relates: https://pagure.io/389-ds-base/issue/51095

Reviewed by: firstyear & tbordaz(Thanks!!)
---
 ldap/servers/plugins/replication/repl5.h      |  2 +-
 .../plugins/replication/repl5_replica.c       | 33 ++++++++------
 ldap/servers/slapd/back-ldbm/ldbm_add.c       |  8 +++-
 ldap/servers/slapd/back-ldbm/ldbm_delete.c    |  9 +++-
 ldap/servers/slapd/back-ldbm/ldbm_modify.c    | 10 ++++-
 ldap/servers/slapd/back-ldbm/ldbm_modrdn.c    |  8 +++-
 ldap/servers/slapd/csngen.c                   | 18 +++++++-
 ldap/servers/slapd/entrywsi.c                 | 15 ++++---
 ldap/servers/slapd/slap.h                     |  2 +-
 ldap/servers/slapd/slapi-plugin.h             |  8 ++++
 ldap/servers/slapd/slapi-private.h            |  5 ++-
 ldap/servers/slapd/time.c                     | 43 +++++++++++++------
 12 files changed, 118 insertions(+), 43 deletions(-)

diff --git a/ldap/servers/plugins/replication/repl5.h b/ldap/servers/plugins/replication/repl5.h
index 72b7089e3..638471744 100644
--- a/ldap/servers/plugins/replication/repl5.h
+++ b/ldap/servers/plugins/replication/repl5.h
@@ -776,7 +776,7 @@ void replica_disable_replication(Replica *r);
 int replica_start_agreement(Replica *r, Repl_Agmt *ra);
 int windows_replica_start_agreement(Replica *r, Repl_Agmt *ra);
 
-CSN *replica_generate_next_csn(Slapi_PBlock *pb, const CSN *basecsn);
+int32_t replica_generate_next_csn(Slapi_PBlock *pb, const CSN *basecsn, CSN **opcsn);
 int replica_get_attr(Slapi_PBlock *pb, const char *type, void *value);
 
 /* mapping tree extensions manipulation */
diff --git a/ldap/servers/plugins/replication/repl5_replica.c b/ldap/servers/plugins/replication/repl5_replica.c
index 02caa88d9..f01782330 100644
--- a/ldap/servers/plugins/replication/repl5_replica.c
+++ b/ldap/servers/plugins/replication/repl5_replica.c
@@ -3931,11 +3931,9 @@ windows_replica_start_agreement(Replica *r, Repl_Agmt *ra)
  * A callback function registered as op->o_csngen_handler and
  * called by backend ops to generate opcsn.
  */
-CSN *
-replica_generate_next_csn(Slapi_PBlock *pb, const CSN *basecsn)
+int32_t
+replica_generate_next_csn(Slapi_PBlock *pb, const CSN *basecsn, CSN **opcsn)
 {
-    CSN *opcsn = NULL;
-
     Replica *replica = replica_get_replica_for_op(pb);
     if (NULL != replica) {
         Slapi_Operation *op;
@@ -3946,17 +3944,26 @@ replica_generate_next_csn(Slapi_PBlock *pb, const CSN *basecsn)
                 CSNGen *gen = (CSNGen *)object_get_data(gen_obj);
                 if (NULL != gen) {
                     /* The new CSN should be greater than the base CSN */
-                    csngen_new_csn(gen, &opcsn, PR_FALSE /* don't notify */);
-                    if (csn_compare(opcsn, basecsn) <= 0) {
-                        char opcsnstr[CSN_STRSIZE], basecsnstr[CSN_STRSIZE];
+                    if (csngen_new_csn(gen, opcsn, PR_FALSE /* don't notify */) != CSN_SUCCESS) {
+                        /* Failed to generate CSN we must abort */
+                        object_release(gen_obj);
+                        return -1;
+                    }
+                    if (csn_compare(*opcsn, basecsn) <= 0) {
+                        char opcsnstr[CSN_STRSIZE];
+                        char basecsnstr[CSN_STRSIZE];
                         char opcsn2str[CSN_STRSIZE];
 
-                        csn_as_string(opcsn, PR_FALSE, opcsnstr);
+                        csn_as_string(*opcsn, PR_FALSE, opcsnstr);
                         csn_as_string(basecsn, PR_FALSE, basecsnstr);
-                        csn_free(&opcsn);
+                        csn_free(opcsn);
                         csngen_adjust_time(gen, basecsn);
-                        csngen_new_csn(gen, &opcsn, PR_FALSE /* don't notify */);
-                        csn_as_string(opcsn, PR_FALSE, opcsn2str);
+                        if (csngen_new_csn(gen, opcsn, PR_FALSE) != CSN_SUCCESS) {
+                            /* Failed to generate CSN we must abort */
+                            object_release(gen_obj);
+                            return -1;
+                        }
+                        csn_as_string(*opcsn, PR_FALSE, opcsn2str);
                         slapi_log_err(SLAPI_LOG_WARNING, repl_plugin_name,
                                       "replica_generate_next_csn - "
                                       "opcsn=%s <= basecsn=%s, adjusted opcsn=%s\n",
@@ -3966,14 +3973,14 @@ replica_generate_next_csn(Slapi_PBlock *pb, const CSN *basecsn)
                      * Insert opcsn into the csn pending list.
                      * This is the notify effect in csngen_new_csn().
                      */
-                    assign_csn_callback(opcsn, (void *)replica);
+                    assign_csn_callback(*opcsn, (void *)replica);
                 }
                 object_release(gen_obj);
             }
         }
     }
 
-    return opcsn;
+    return 0;
 }
 
 /*
diff --git a/ldap/servers/slapd/back-ldbm/ldbm_add.c b/ldap/servers/slapd/back-ldbm/ldbm_add.c
index d0d88bf16..ee366c74c 100644
--- a/ldap/servers/slapd/back-ldbm/ldbm_add.c
+++ b/ldap/servers/slapd/back-ldbm/ldbm_add.c
@@ -645,7 +645,13 @@ ldbm_back_add(Slapi_PBlock *pb)
                          * Current op is a user request. Opcsn will be assigned
                          * if the dn is in an updatable replica.
                          */
-                        opcsn = entry_assign_operation_csn(pb, e, parententry ? parententry->ep_entry : NULL);
+                        if (entry_assign_operation_csn(pb, e, parententry ? parententry->ep_entry : NULL, &opcsn) != 0) {
+                            slapi_log_err(SLAPI_LOG_ERR, "ldbm_back_add",
+                                    "failed to generate add CSN for entry (%s), aborting operation\n",
+                                    slapi_entry_get_dn(e));
+                            ldap_result_code = LDAP_OPERATIONS_ERROR;
+                            goto error_return;
+                        }
                     }
                     if (opcsn != NULL) {
                         entry_set_csn(e, opcsn);
diff --git a/ldap/servers/slapd/back-ldbm/ldbm_delete.c b/ldap/servers/slapd/back-ldbm/ldbm_delete.c
index 873b5b00e..fbcb57310 100644
--- a/ldap/servers/slapd/back-ldbm/ldbm_delete.c
+++ b/ldap/servers/slapd/back-ldbm/ldbm_delete.c
@@ -464,7 +464,14 @@ replace_entry:
                      * by entry_assign_operation_csn() if the dn is in an
                      * updatable replica.
                      */
-                    opcsn = entry_assign_operation_csn ( pb, e->ep_entry, NULL );
+                    if (entry_assign_operation_csn(pb, e->ep_entry, NULL, &opcsn) != 0) {
+                        slapi_log_err(SLAPI_LOG_ERR, "ldbm_back_delete",
+                                "failed to generate delete CSN for entry (%s), aborting operation\n",
+                                slapi_entry_get_dn(e->ep_entry));
+                        retval = -1;
+                        ldap_result_code = LDAP_OPERATIONS_ERROR;
+                        goto error_return;
+                    }
                 }
                 if (opcsn != NULL) {
                     if (!is_fixup_operation) {
diff --git a/ldap/servers/slapd/back-ldbm/ldbm_modify.c b/ldap/servers/slapd/back-ldbm/ldbm_modify.c
index b0c477e3f..e9d7e87e3 100644
--- a/ldap/servers/slapd/back-ldbm/ldbm_modify.c
+++ b/ldap/servers/slapd/back-ldbm/ldbm_modify.c
@@ -598,12 +598,18 @@ ldbm_back_modify(Slapi_PBlock *pb)
                     goto error_return;
                 }
                 opcsn = operation_get_csn(operation);
-                if (NULL == opcsn && operation->o_csngen_handler) {
+                if (opcsn == NULL && operation->o_csngen_handler) {
                     /*
                      * Current op is a user request. Opcsn will be assigned
                      * if the dn is in an updatable replica.
                      */
-                    opcsn = entry_assign_operation_csn(pb, e->ep_entry, NULL);
+                    if (entry_assign_operation_csn(pb, e->ep_entry, NULL, &opcsn) != 0) {
+                        slapi_log_err(SLAPI_LOG_ERR, "ldbm_back_modify",
+                                "failed to generate modify CSN for entry (%s), aborting operation\n",
+                                slapi_entry_get_dn(e->ep_entry));
+                        ldap_result_code = LDAP_OPERATIONS_ERROR;
+                        goto error_return;
+                    }
                 }
                 if (opcsn) {
                     entry_set_maxcsn(e->ep_entry, opcsn);
diff --git a/ldap/servers/slapd/back-ldbm/ldbm_modrdn.c b/ldap/servers/slapd/back-ldbm/ldbm_modrdn.c
index 26698012a..fde83c99f 100644
--- a/ldap/servers/slapd/back-ldbm/ldbm_modrdn.c
+++ b/ldap/servers/slapd/back-ldbm/ldbm_modrdn.c
@@ -543,7 +543,13 @@ ldbm_back_modrdn(Slapi_PBlock *pb)
                      * Current op is a user request. Opcsn will be assigned
                      * if the dn is in an updatable replica.
                      */
-                    opcsn = entry_assign_operation_csn(pb, e->ep_entry, parententry ? parententry->ep_entry : NULL);
+                    if (entry_assign_operation_csn(pb, e->ep_entry, parententry ? parententry->ep_entry : NULL, &opcsn) != 0) {
+                        slapi_log_err(SLAPI_LOG_ERR, "ldbm_back_modrdn",
+                                "failed to generate modrdn CSN for entry (%s), aborting operation\n",
+                                slapi_entry_get_dn(e->ep_entry));
+                        ldap_result_code = LDAP_OPERATIONS_ERROR;
+                        goto error_return;
+                    }
                 }
                 if (opcsn != NULL) {
                     entry_set_maxcsn(e->ep_entry, opcsn);
diff --git a/ldap/servers/slapd/csngen.c b/ldap/servers/slapd/csngen.c
index 68dbbda8e..b08d8b25c 100644
--- a/ldap/servers/slapd/csngen.c
+++ b/ldap/servers/slapd/csngen.c
@@ -164,6 +164,7 @@ csngen_free(CSNGen **gen)
 int
 csngen_new_csn(CSNGen *gen, CSN **csn, PRBool notify)
 {
+    struct timespec now = {0};
     int rc = CSN_SUCCESS;
     time_t cur_time;
     int delta;
@@ -179,12 +180,25 @@ csngen_new_csn(CSNGen *gen, CSN **csn, PRBool notify)
         return CSN_MEMORY_ERROR;
     }
 
-    slapi_rwlock_wrlock(gen->lock);
+    if ((rc = slapi_clock_gettime(&now)) != 0) {
+        /* Failed to get system time, we must abort */
+        slapi_log_err(SLAPI_LOG_ERR, "csngen_new_csn",
+                "Failed to get system time (%s)\n",
+                slapd_system_strerror(rc));
+        return CSN_TIME_ERROR;
+    }
+    cur_time = now.tv_sec;
 
-    cur_time = slapi_current_utc_time();
+    slapi_rwlock_wrlock(gen->lock);
 
     /* check if the time should be adjusted */
     delta = cur_time - gen->state.sampled_time;
+    if (delta > _SEC_PER_DAY || delta < (-1 * _SEC_PER_DAY)) {
+        /* We had a jump larger than a day */
+        slapi_log_err(SLAPI_LOG_INFO, "csngen_new_csn",
+                "Detected large jump in CSN time.  Delta: %d (current time: %ld  vs  previous time: %ld)\n",
+                delta, cur_time, gen->state.sampled_time);
+    }
     if (delta > 0) {
         rc = _csngen_adjust_local_time(gen, cur_time);
         if (rc != CSN_SUCCESS) {
diff --git a/ldap/servers/slapd/entrywsi.c b/ldap/servers/slapd/entrywsi.c
index 5d1d7238a..31bf65d8e 100644
--- a/ldap/servers/slapd/entrywsi.c
+++ b/ldap/servers/slapd/entrywsi.c
@@ -224,13 +224,12 @@ entry_add_rdn_csn(Slapi_Entry *e, const CSN *csn)
     slapi_rdn_free(&rdn);
 }
 
-CSN *
-entry_assign_operation_csn(Slapi_PBlock *pb, Slapi_Entry *e, Slapi_Entry *parententry)
+int32_t
+entry_assign_operation_csn(Slapi_PBlock *pb, Slapi_Entry *e, Slapi_Entry *parententry, CSN **opcsn)
 {
     Slapi_Operation *op;
     const CSN *basecsn = NULL;
     const CSN *parententry_dncsn = NULL;
-    CSN *opcsn = NULL;
 
     slapi_pblock_get(pb, SLAPI_OPERATION, &op);
 
@@ -252,14 +251,16 @@ entry_assign_operation_csn(Slapi_PBlock *pb, Slapi_Entry *e, Slapi_Entry *parent
                 basecsn = parententry_dncsn;
             }
         }
-        opcsn = op->o_csngen_handler(pb, basecsn);
+        if(op->o_csngen_handler(pb, basecsn, opcsn) != 0) {
+            return -1;
+        }
 
-        if (NULL != opcsn) {
-            operation_set_csn(op, opcsn);
+        if (*opcsn) {
+            operation_set_csn(op, *opcsn);
         }
     }
 
-    return opcsn;
+    return 0;
 }
 
 /*
diff --git a/ldap/servers/slapd/slap.h b/ldap/servers/slapd/slap.h
index a4cae784a..cef8c789c 100644
--- a/ldap/servers/slapd/slap.h
+++ b/ldap/servers/slapd/slap.h
@@ -1480,7 +1480,7 @@ struct op;
 typedef void (*result_handler)(struct conn *, struct op *, int, char *, char *, int, struct berval **);
 typedef int (*search_entry_handler)(Slapi_Backend *, struct conn *, struct op *, struct slapi_entry *);
 typedef int (*search_referral_handler)(Slapi_Backend *, struct conn *, struct op *, struct berval **);
-typedef CSN *(*csngen_handler)(Slapi_PBlock *pb, const CSN *basecsn);
+typedef int32_t *(*csngen_handler)(Slapi_PBlock *pb, const CSN *basecsn, CSN **opcsn);
 typedef int (*replica_attr_handler)(Slapi_PBlock *pb, const char *type, void **value);
 
 /*
diff --git a/ldap/servers/slapd/slapi-plugin.h b/ldap/servers/slapd/slapi-plugin.h
index be1e52e4d..834a98742 100644
--- a/ldap/servers/slapd/slapi-plugin.h
+++ b/ldap/servers/slapd/slapi-plugin.h
@@ -6743,6 +6743,14 @@ int slapi_reslimit_get_integer_limit(Slapi_Connection *conn, int handle, int *li
  */
 time_t slapi_current_time(void) __attribute__((deprecated));
 
+/**
+ * Get the system time and check for errors.  Return
+ *
+ * \param tp - a timespec struct where the system time is set
+ * \return result code, upon success tp is set to the system time
+ */
+int32_t slapi_clock_gettime(struct timespec *tp);
+
 /**
  * Returns the current system time as a hr clock relative to uptime
  * This means the clock is not affected by timezones
diff --git a/ldap/servers/slapd/slapi-private.h b/ldap/servers/slapd/slapi-private.h
index d85ee43e5..c98c1947c 100644
--- a/ldap/servers/slapd/slapi-private.h
+++ b/ldap/servers/slapd/slapi-private.h
@@ -233,7 +233,8 @@ enum
     CSN_INVALID_PARAMETER, /* invalid function argument */
     CSN_INVALID_FORMAT,    /* invalid state format */
     CSN_LDAP_ERROR,        /* LDAP operation failed */
-    CSN_NSPR_ERROR         /* NSPR API failure */
+    CSN_NSPR_ERROR,        /* NSPR API failure */
+    CSN_TIME_ERROR         /* Error generating new CSN due to clock failure */
 };
 
 typedef struct csngen CSNGen;
@@ -326,7 +327,7 @@ int slapi_entries_diff(Slapi_Entry **old_entries, Slapi_Entry **new_entries, int
 void set_attr_to_protected_list(char *attr, int flag);
 
 /* entrywsi.c */
-CSN *entry_assign_operation_csn(Slapi_PBlock *pb, Slapi_Entry *e, Slapi_Entry *parententry);
+int32_t entry_assign_operation_csn(Slapi_PBlock *pb, Slapi_Entry *e, Slapi_Entry *parententry, CSN **opcsn);
 const CSN *entry_get_maxcsn(const Slapi_Entry *entry);
 void entry_set_maxcsn(Slapi_Entry *entry, const CSN *csn);
 const CSN *entry_get_dncsn(const Slapi_Entry *entry);
diff --git a/ldap/servers/slapd/time.c b/ldap/servers/slapd/time.c
index 8048a3359..545538404 100644
--- a/ldap/servers/slapd/time.c
+++ b/ldap/servers/slapd/time.c
@@ -61,6 +61,25 @@ poll_current_time()
     return 0;
 }
 
+/*
+ * Check if the time function returns an error.  If so return the errno
+ */
+int32_t
+slapi_clock_gettime(struct timespec *tp)
+{
+    int32_t rc = 0;
+
+    PR_ASSERT(tp && tp->tv_nsec == 0 && tp->tv_sec == 0);
+
+    if (clock_gettime(CLOCK_REALTIME, tp) != 0) {
+        rc = errno;
+    }
+
+    PR_ASSERT(rc == 0);
+
+    return rc;
+}
+
 time_t
 current_time(void)
 {
@@ -69,7 +88,7 @@ current_time(void)
      * but this should be removed in favour of the
      * more accurately named slapi_current_utc_time
      */
-    struct timespec now;
+    struct timespec now = {0};
     clock_gettime(CLOCK_REALTIME, &now);
     return now.tv_sec;
 }
@@ -83,7 +102,7 @@ slapi_current_time(void)
 struct timespec
 slapi_current_rel_time_hr(void)
 {
-    struct timespec now;
+    struct timespec now = {0};
     clock_gettime(CLOCK_MONOTONIC, &now);
     return now;
 }
@@ -91,7 +110,7 @@ slapi_current_rel_time_hr(void)
 struct timespec
 slapi_current_utc_time_hr(void)
 {
-    struct timespec ltnow;
+    struct timespec ltnow = {0};
     clock_gettime(CLOCK_REALTIME, &ltnow);
     return ltnow;
 }
@@ -99,7 +118,7 @@ slapi_current_utc_time_hr(void)
 time_t
 slapi_current_utc_time(void)
 {
-    struct timespec ltnow;
+    struct timespec ltnow = {0};
     clock_gettime(CLOCK_REALTIME, &ltnow);
     return ltnow.tv_sec;
 }
@@ -108,8 +127,8 @@ void
 slapi_timestamp_utc_hr(char *buf, size_t bufsize)
 {
     PR_ASSERT(bufsize >= SLAPI_TIMESTAMP_BUFSIZE);
-    struct timespec ltnow;
-    struct tm utctm;
+    struct timespec ltnow = {0};
+    struct tm utctm = {0};
     clock_gettime(CLOCK_REALTIME, &ltnow);
     gmtime_r(&(ltnow.tv_sec), &utctm);
     strftime(buf, bufsize, "%Y%m%d%H%M%SZ", &utctm);
@@ -140,7 +159,7 @@ format_localTime_log(time_t t, int initsize __attribute__((unused)), char *buf,
 {
 
     long tz;
-    struct tm *tmsp, tms;
+    struct tm *tmsp, tms = {0};
     char tbuf[*bufsize];
     char sign;
     /* make sure our buffer will be big enough. Need at least 29 */
@@ -191,7 +210,7 @@ format_localTime_hr_log(time_t t, long nsec, int initsize __attribute__((unused)
 {
 
     long tz;
-    struct tm *tmsp, tms;
+    struct tm *tmsp, tms = {0};
     char tbuf[*bufsize];
     char sign;
     /* make sure our buffer will be big enough. Need at least 39 */
@@ -278,7 +297,7 @@ slapi_timespec_expire_check(struct timespec *expire)
     if (expire->tv_sec == 0 && expire->tv_nsec == 0) {
         return TIMER_CONTINUE;
     }
-    struct timespec now;
+    struct timespec now = {0};
     clock_gettime(CLOCK_MONOTONIC, &now);
     if (now.tv_sec > expire->tv_sec ||
         (expire->tv_sec == now.tv_sec && now.tv_sec > expire->tv_nsec)) {
@@ -293,7 +312,7 @@ format_localTime(time_t from)
        in the syntax of a generalizedTime, except without the time zone. */
 {
     char *into;
-    struct tm t;
+    struct tm t = {0};
 
     localtime_r(&from, &t);
 
@@ -362,7 +381,7 @@ format_genTime(time_t from)
        in the syntax of a generalizedTime. */
 {
     char *into;
-    struct tm t;
+    struct tm t = {0};
 
     gmtime_r(&from, &t);
     into = slapi_ch_malloc(SLAPI_TIMESTAMP_BUFSIZE);
@@ -382,7 +401,7 @@ time_t
 read_genTime(struct berval *from)
 {
     struct tm t = {0};
-    time_t retTime;
+    time_t retTime = {0};
     time_t diffsec = 0;
     int i, gflag = 0, havesec = 0;
 
-- 
2.26.2