fix: a potential deadlock in chain follower fork handling

CHANGELOG.md

@@ -57,6 +57,8 @@
 
 - [#6234](https://github.com/ChainSafe/forest/pull/6234) Support `input` as an alias for `data` in `eth_call` and `eth_estimateGas` RPC methods.
 
+- [#6235](https://github.com/ChainSafe/forest/pull/6235) Fixed a potential deadlock in chain follower when handling fork(s).
+
 ## Forest v0.30.2 "Garuda"
 
 This is a non-mandatory release that brings important enhancements to Forest's tooling capabilities, Ethereum RPC compatibility, and F3 integration.

src/chain_sync/chain_follower.rs

@@ -584,7 +584,7 @@ impl<DB: Blockstore> SyncStateMachine<DB> {
         chains
     }
 
-    fn is_validated(&self, tipset: &FullTipset) -> bool {
+    fn is_parent_validated(&self, tipset: &FullTipset) -> bool {
         let db = self.cs.blockstore();
         self.stateless_mode || db.has(tipset.parent_state()).unwrap_or(false)
     }
@@ -605,7 +605,7 @@ impl<DB: Blockstore> SyncStateMachine<DB> {
             } else if parent_ts.epoch() >= head_ts.epoch() {
                 false
             } else {
-                self.is_validated(&parent_ts)
+                self.is_parent_validated(tipset)
             }
         } else {
             false
@@ -711,7 +711,7 @@ impl<DB: Blockstore> SyncStateMachine<DB> {
     }
 
     fn mark_validated_tipset(&mut self, tipset: Arc<FullTipset>, is_proposed_head: bool) {
-        if !self.is_validated(&tipset) {
+        if !self.is_parent_validated(&tipset) {
             tracing::error!(epoch = %tipset.epoch(), tsk = %tipset.key(), "Tipset must be validated");
             return;
         }