isisd: Fix memory leaks when the transition of neighbor state from non-UP to DOWN

When receiving a hello packet, if the neighbor state transitions directly from a non-ISIS_ADJ_UP state (such as ISIS_ADJ_INITIALIZING) to ISIS_ADJ_DOWN state, the neighbor entry cannot be deleted. If the neighbor is removed or the neighbor's System ID changes, it may result in memory leakage in the neighbor entry.

Test Scenario:
LAN link between Router A and Router B is established. Router A does not configure neighbor authentication, while Router B is configured with neighbor authentication. When the neighbor entry on Router B ages out, the neighbor state on Router A transitions to INIT. If Router B is then removed, the neighbor state on Router A transitions to DOWN and persists.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>
fix frrbot styling issues found.

fix frrbot styling issues found.

Signed-off-by: zhou-run <166502045+zhou-run@users.noreply.github.com>
(cherry picked from commit 5009f7539ad6bf496158499917dcf3f7ab760753)

diff --git a/isisd/isis_adjacency.c b/isisd/isis_adjacency.c
index cba1b91faef12008fb5c1b0f91289c9bd43fd494..32d3466f5c4be672a6f5af4b275f54bf6d2b5cc8 100644 (file)
--- a/isisd/isis_adjacency.c
+++ b/isisd/isis_adjacency.c
@@ -358,12 +358,15 @@ void isis_adj_state_change(struct isis_adjacency **padj,
                                 * purposes */
                                adj->last_flap = time(NULL);
                                adj->flaps++;
-                       } else if (old_state == ISIS_ADJ_UP) {
-                               circuit->adj_state_changes++;
+                       } else {
+                               if (old_state == ISIS_ADJ_UP) {
+                                       circuit->adj_state_changes++;
 
-                               circuit->upadjcount[level - 1]--;
-                               if (circuit->upadjcount[level - 1] == 0)
-                                       isis_tx_queue_clean(circuit->tx_queue);
+                                       circuit->upadjcount[level - 1]--;
+                                       if (circuit->upadjcount[level - 1] == 0)
+                                               isis_tx_queue_clean(
+                                                       circuit->tx_queue);
+                               }
 
                                if (new_state == ISIS_ADJ_DOWN) {
                                        listnode_delete(
@@ -409,10 +412,13 @@ void isis_adj_state_change(struct isis_adjacency **padj,
                                                master, send_l2_csnp, circuit,
                                                0, &circuit->t_send_csnp[1]);
                                }
-                       } else if (old_state == ISIS_ADJ_UP) {
-                               circuit->upadjcount[level - 1]--;
-                               if (circuit->upadjcount[level - 1] == 0)
-                                       isis_tx_queue_clean(circuit->tx_queue);
+                       } else {
+                               if (old_state == ISIS_ADJ_UP) {
+                                       circuit->upadjcount[level - 1]--;
+                                       if (circuit->upadjcount[level - 1] == 0)
+                                               isis_tx_queue_clean(
+                                                       circuit->tx_queue);
+                               }
 
                                if (new_state == ISIS_ADJ_DOWN) {
                                        if (adj->circuit->u.p2p.neighbor == adj)