Merge branch 'rickard/creation-fix/25.3.1/OTP-18570' into maint

* rickard/creation-fix/25.3.1/OTP-18570:
  [erts] ensure no mix of external and internal identifiers

3 files changed, 33 insertions, 0 deletions

diff --git a/erts/emulator/beam/dist.c b/erts/emulator/beam/dist.c
index 550d4301a2..2a2c4fd31b 100644
--- a/erts/emulator/beam/dist.c
+++ b/erts/emulator/beam/dist.c
@@ -4906,6 +4906,19 @@ BIF_RETTYPE setnode_2(BIF_ALIST_2)
     success = (!ERTS_PROC_IS_EXITING(net_kernel)
                & !ERTS_PROC_GET_DIST_ENTRY(net_kernel));
     if (success) {
+        /*
+         * Ensure we don't use a nodename-creation pair with
+         * external identifiers existing in the system.
+         */
+        while (!0) {
+            ErlNode *nep;
+            if (creation < 4)
+                creation = 4;
+            nep = erts_find_node(BIF_ARG_1, creation);
+            if (!nep || erts_node_refc(nep) == 0)
+                break;
+            creation++;
+        }
         inc_no_nodes();
         erts_set_this_node(BIF_ARG_1, (Uint32) creation);
         erts_this_dist_entry->creation = creation;
diff --git a/erts/emulator/beam/erl_node_tables.c b/erts/emulator/beam/erl_node_tables.c
index 2bec8ff20e..c2d9b0967d 100644
--- a/erts/emulator/beam/erl_node_tables.c
+++ b/erts/emulator/beam/erl_node_tables.c
@@ -885,6 +885,18 @@ erts_node_table_info(fmtfn_t to, void *to_arg)
 	erts_rwmtx_runlock(&erts_node_table_rwmtx);
 }
 
+ErlNode *erts_find_node(Eterm sysname, Uint32 creation)
+{
+    ErlNode *res;
+    ErlNode ne;
+    ne.sysname = sysname;
+    ne.creation = creation;
+
+    erts_rwmtx_rlock(&erts_node_table_rwmtx);
+    res = hash_get(&erts_node_table, (void *) &ne);
+    erts_rwmtx_runlock(&erts_node_table_rwmtx);
+    return res;
+}
 
 ErlNode *erts_find_or_insert_node(Eterm sysname, Uint32 creation, Eterm book)
 {
diff --git a/erts/emulator/beam/erl_node_tables.h b/erts/emulator/beam/erl_node_tables.h
index c12198a23c..56696586c6 100644
--- a/erts/emulator/beam/erl_node_tables.h
+++ b/erts/emulator/beam/erl_node_tables.h
@@ -255,6 +255,7 @@ void erts_set_dist_entry_not_connected(DistEntry *);
 void erts_set_dist_entry_pending(DistEntry *);
 void erts_set_dist_entry_connected(DistEntry *, Eterm, Uint64);
 ErlNode *erts_find_or_insert_node(Eterm, Uint32, Eterm);
+ErlNode *erts_find_node(Eterm, Uint32);
 void erts_schedule_delete_node(ErlNode *);
 void erts_set_this_node(Eterm, Uint32);
 Uint erts_node_table_size(void);
@@ -282,6 +283,7 @@ ERTS_GLB_INLINE void erts_deref_node_entry__(ErlNode *np, Eterm term, char *file
 ERTS_GLB_INLINE erts_aint_t erts_ref_node_entry(ErlNode *np, int min_val, Eterm term);
 ERTS_GLB_INLINE void erts_deref_node_entry(ErlNode *np, Eterm term);
 #endif
+ERTS_GLB_INLINE erts_aint_t erts_node_refc(ErlNode *np);
 ERTS_GLB_INLINE void erts_de_rlock(DistEntry *dep);
 ERTS_GLB_INLINE void erts_de_runlock(DistEntry *dep);
 ERTS_GLB_INLINE void erts_de_rwlock(DistEntry *dep);
@@ -332,6 +334,12 @@ erts_deref_node_entry(ErlNode *np, Eterm term)
 	erts_schedule_delete_node(np);
 }
 
+ERTS_GLB_INLINE erts_aint_t
+erts_node_refc(ErlNode *np)
+{
+    return erts_refc_read(&np->refc, 0);
+}
+
 #endif
 
 ERTS_GLB_INLINE void