From f0aaf655533cf838cb3470de0be9936ef500815e Mon Sep 17 00:00:00 2001
From: Lion - dapplion <35266934+dapplion@users.noreply.github.com>
Date: Mon, 1 Jun 2026 08:17:00 +0200
Subject: [PATCH] Use correct slot in custody request (#9380)

Co-Authored-By: dapplion <35266934+dapplion@users.noreply.github.com>
---
 .../network/src/sync/block_lookups/common.rs  |  2 +-
 .../sync/block_lookups/single_block_lookup.rs |  6 +++--
 .../network/src/sync/network_context.rs       | 22 +++----------------
 3 files changed, 8 insertions(+), 22 deletions(-)

diff --git a/beacon_node/network/src/sync/block_lookups/common.rs b/beacon_node/network/src/sync/block_lookups/common.rs
index edd99345b4..bf11f0b658 100644
--- a/beacon_node/network/src/sync/block_lookups/common.rs
+++ b/beacon_node/network/src/sync/block_lookups/common.rs
@@ -172,7 +172,7 @@ impl<T: BeaconChainTypes> RequestState<T> for CustodyRequestState<T::EthSpec> {
         _: usize,
         cx: &mut SyncNetworkContext<T>,
     ) -> Result<LookupRequestResult, LookupRequestError> {
-        cx.custody_lookup_request(id, self.block_root, lookup_peers)
+        cx.custody_lookup_request(id, self.block_root, self.slot, lookup_peers)
             .map_err(LookupRequestError::SendFailedNetwork)
     }
 
diff --git a/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs b/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
index d54480e8e5..536a8c5cb0 100644
--- a/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
+++ b/beacon_node/network/src/sync/block_lookups/single_block_lookup.rs
@@ -239,7 +239,7 @@ impl<T: BeaconChainTypes> SingleBlockLookup<T> {
                     );
                 } else if cx.chain.should_fetch_custody_columns(block_epoch) {
                     self.component_requests = ComponentRequests::ActiveCustodyRequest(
-                        CustodyRequestState::new(self.block_root),
+                        CustodyRequestState::new(self.block_root, block.slot()),
                     );
                 } else {
                     self.component_requests = ComponentRequests::NotNeeded("outside da window");
@@ -397,13 +397,15 @@ impl<E: EthSpec> BlobRequestState<E> {
 pub struct CustodyRequestState<E: EthSpec> {
     #[educe(Debug(ignore))]
     pub block_root: Hash256,
+    pub slot: Slot,
     pub state: SingleLookupRequestState<DataColumnSidecarList<E>>,
 }
 
 impl<E: EthSpec> CustodyRequestState<E> {
-    pub fn new(block_root: Hash256) -> Self {
+    pub fn new(block_root: Hash256, slot: Slot) -> Self {
         Self {
             block_root,
+            slot,
             state: SingleLookupRequestState::new(),
         }
     }
diff --git a/beacon_node/network/src/sync/network_context.rs b/beacon_node/network/src/sync/network_context.rs
index 9d5ac40c0a..3aaf4dbaa0 100644
--- a/beacon_node/network/src/sync/network_context.rs
+++ b/beacon_node/network/src/sync/network_context.rs
@@ -1174,34 +1174,18 @@ impl<T: BeaconChainTypes> SyncNetworkContext<T> {
         &mut self,
         lookup_id: SingleLookupId,
         block_root: Hash256,
+        block_slot: Slot,
         lookup_peers: Arc<RwLock<HashSet<PeerId>>>,
     ) -> Result<LookupRequestResult, RpcRequestSendError> {
-        let slot = self
-            .chain
-            .canonical_head
-            .fork_choice_read_lock()
-            .get_block(&block_root)
-            .map(|block| block.slot)
-            .or_else(|| self.chain.slot().ok())
-            .ok_or_else(|| {
-                RpcRequestSendError::InternalError(format!(
-                    "Unable to determine slot for block {block_root:?}"
-                ))
-            })?;
-
         let custody_indexes_imported = self
             .chain
-            .cached_data_column_indexes(&block_root, slot)
+            .cached_data_column_indexes(&block_root, block_slot)
             .unwrap_or_default();
 
-        let current_epoch = self.chain.epoch().map_err(|e| {
-            RpcRequestSendError::InternalError(format!("Unable to read slot clock {:?}", e))
-        })?;
-
         // Include only the blob indexes not yet imported (received through gossip)
         let mut custody_indexes_to_fetch = self
             .chain
-            .sampling_columns_for_epoch(current_epoch)
+            .sampling_columns_for_epoch(block_slot.epoch(T::EthSpec::slots_per_epoch()))
             .iter()
             .copied()
             .filter(|index| !custody_indexes_imported.contains(index))