network: do not drop duplicated entries in loop

Fixes #37456.

src/network/networkd-address.c

@@ -2393,16 +2393,22 @@ int address_section_verify(Address *address) {
         return 0;
 }
 
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
+        trivial_hash_ops_address_detach,
+        void,
+        trivial_hash_func,
+        trivial_compare_func,
+        Address,
+        address_detach);
+
 int network_drop_invalid_addresses(Network *network) {
-        _cleanup_set_free_ Set *addresses = NULL;
+        _cleanup_set_free_ Set *addresses = NULL, *duplicated_addresses = NULL;
         Address *address;
         int r;
 
         assert(network);
 
         ORDERED_HASHMAP_FOREACH(address, network->addresses_by_section) {
-                Address *dup;
-
                 if (address_section_verify(address) < 0) {
                         /* Drop invalid [Address] sections or Address= settings in [Network].
                          * Note that address_detach() will drop the address from addresses_by_section. */
@@ -2411,7 +2417,7 @@ int network_drop_invalid_addresses(Network *network) {
                 }
 
                 /* Always use the setting specified later. So, remove the previously assigned setting. */
-                dup = set_remove(addresses, address);
+                Address *dup = set_remove(addresses, address);
                 if (dup) {
                         log_warning("%s: Duplicated address %s is specified at line %u and %u, "
                                     "dropping the address setting specified at line %u.",
@@ -2420,8 +2426,12 @@ int network_drop_invalid_addresses(Network *network) {
                                     address->section->line,
                                     dup->section->line, dup->section->line);
 
-                        /* address_detach() will drop the address from addresses_by_section. */
-                        address_detach(dup);
+                        /* Do not call address_detach() for 'dup' now, as we can remove only the current
+                         * entry in the loop. We will drop the address from addresses_by_section later. */
+                        r = set_ensure_put(&duplicated_addresses, &trivial_hash_ops_address_detach, dup);
+                        if (r < 0)
+                                return log_oom();
+                        assert(r > 0);
                 }
 
                 /* Use address_hash_ops, instead of address_hash_ops_detach. Otherwise, the Address objects

src/network/networkd-neighbor.c

@@ -682,8 +682,16 @@ static int neighbor_section_verify(Neighbor *neighbor) {
         return 0;
 }
 
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
+        trivial_hash_ops_neighbor_detach,
+        void,
+        trivial_hash_func,
+        trivial_compare_func,
+        Neighbor,
+        neighbor_detach);
+
 int network_drop_invalid_neighbors(Network *network) {
-        _cleanup_set_free_ Set *neighbors = NULL;
+        _cleanup_set_free_ Set *neighbors = NULL, *duplicated_neighbors = NULL;
         Neighbor *neighbor;
         int r;
 
@@ -708,8 +716,13 @@ int network_drop_invalid_neighbors(Network *network) {
                                     IN_ADDR_TO_STRING(neighbor->dst_addr.family, &neighbor->dst_addr.address),
                                     neighbor->section->line,
                                     dup->section->line, dup->section->line);
-                        /* neighbor_detach() will drop the neighbor from neighbors_by_section. */
-                        neighbor_detach(dup);
+
+                        /* Do not call nexthop_detach() for 'dup' now, as we can remove only the current
+                         * entry in the loop. We will drop the nexthop from nexthops_by_section later. */
+                        r = set_ensure_put(&duplicated_neighbors, &trivial_hash_ops_neighbor_detach, dup);
+                        if (r < 0)
+                                return log_oom();
+                        assert(r > 0);
                 }
 
                 /* Use neighbor_hash_ops, instead of neighbor_hash_ops_detach. Otherwise, the Neighbor objects

src/network/networkd-nexthop.c

@@ -1279,6 +1279,7 @@ static int nexthop_section_verify(NextHop *nh) {
 
 int network_drop_invalid_nexthops(Network *network) {
         _cleanup_hashmap_free_ Hashmap *nexthops = NULL;
+        _cleanup_set_free_ Set *duplicated_nexthops = NULL;
         NextHop *nh;
         int r;
 
@@ -1301,8 +1302,13 @@ int network_drop_invalid_nexthops(Network *network) {
                                     dup->section->filename,
                                     nh->id, nh->section->line,
                                     dup->section->line, dup->section->line);
-                        /* nexthop_detach() will drop the nexthop from nexthops_by_section. */
-                        nexthop_detach(dup);
+
+                        /* Do not call nexthop_detach() for 'dup' now, as we can remove only the current
+                         * entry in the loop. We will drop the nexthop from nexthops_by_section later. */
+                        r = set_ensure_put(&duplicated_nexthops, &nexthop_hash_ops, dup);
+                        if (r < 0)
+                                return log_oom();
+                        assert(r > 0);
                 }
 
                 r = hashmap_ensure_put(&nexthops, NULL, UINT32_TO_PTR(nh->id), nh);