From ceed7ff9e65e22baae4ab9fc851517c83a168592 Mon Sep 17 00:00:00 2001
From: Semyon Danilov <senya@ydb.tech>
Date: Fri, 26 Jan 2024 21:03:51 +0000
Subject: [PATCH 1/2] Fix use after free

---
 .../pdisk/blobstorage_pdisk_impl_log.cpp            | 13 +++++--------
 .../blobstorage/pdisk/blobstorage_pdisk_state.h     |  1 +
 2 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp b/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp
index dfa78979f08b..60d0f450502f 100644
--- a/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp
+++ b/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp
@@ -13,27 +13,24 @@ class TLogFlushCompletionAction : public TCompletionAction {
     const ui32 EndChunkIdx;
     const ui32 EndSectorIdx;
     THolder<TLogWriter> &CommonLogger;
+    TCompletionAction* CompletionLogWrite;
 public:
     TLogFlushCompletionAction(ui32 endChunkIdx, ui32 endSectorIdx, THolder<TLogWriter> &commonLogger, TCompletionAction* completionLogWrite)
         : EndChunkIdx(endChunkIdx)
         , EndSectorIdx(endSectorIdx)
-        , CommonLogger(commonLogger) {
-            this->FlushAction = completionLogWrite;
-        }
+        , CommonLogger(commonLogger)
+        , CompletionLogWrite(completionLogWrite) { }
 
     void Exec(TActorSystem *actorSystem) override {
         CommonLogger->FirstUncommitted = TFirstUncommitted(EndChunkIdx, EndSectorIdx);
 
-        Y_DEBUG_ABORT_UNLESS(FlushAction);
-
-        // FlushAction here is a TCompletionLogWrite which will decrease owner's inflight count.
-        FlushAction->Exec(actorSystem);
+        CompletionLogWrite->Exec(actorSystem);
 
         delete this;
     }
 
     void Release(TActorSystem *actorSystem) override {
-        FlushAction->Release(actorSystem);
+        CompletionLogWrite->Release(actorSystem);
 
         delete this;
     }
diff --git a/ydb/core/blobstorage/pdisk/blobstorage_pdisk_state.h b/ydb/core/blobstorage/pdisk/blobstorage_pdisk_state.h
index 5dc1eba7a6c4..641ca889adef 100644
--- a/ydb/core/blobstorage/pdisk/blobstorage_pdisk_state.h
+++ b/ydb/core/blobstorage/pdisk/blobstorage_pdisk_state.h
@@ -196,6 +196,7 @@ struct TOwnerData {
         CurrentFirstLsnToKeep = 0;
         LastWrittenCommitLsn = 0;
         CutLogId = TActorId();
+        LogEndPosition = TLogEndPosition(0, 0);
         WhiteboardProxyId = TActorId();
         LogRecordsInitiallyRead = 0;
         LogRecordsConsequentlyRead = 0;

From 4e2772631f6ab338f5d1a40edf215bd5361963b5 Mon Sep 17 00:00:00 2001
From: Semyon Danilov <senya@ydb.tech>
Date: Mon, 29 Jan 2024 10:53:02 +0000
Subject: [PATCH 2/2] Propagate completion result and error

---
 ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp b/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp
index 60d0f450502f..44d5bb98a11c 100644
--- a/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp
+++ b/ydb/core/blobstorage/pdisk/blobstorage_pdisk_impl_log.cpp
@@ -23,13 +23,17 @@ class TLogFlushCompletionAction : public TCompletionAction {
 
     void Exec(TActorSystem *actorSystem) override {
         CommonLogger->FirstUncommitted = TFirstUncommitted(EndChunkIdx, EndSectorIdx);
-
+        
+        CompletionLogWrite->SetResult(Result);
+        CompletionLogWrite->SetErrorReason(ErrorReason);
         CompletionLogWrite->Exec(actorSystem);
 
         delete this;
     }
 
     void Release(TActorSystem *actorSystem) override {
+        CompletionLogWrite->SetResult(Result);
+        CompletionLogWrite->SetErrorReason(ErrorReason);
         CompletionLogWrite->Release(actorSystem);
 
         delete this;