From: Sage Weil <sage@redhat.com>
Date: Tue, 7 Aug 2018 22:02:56 +0000 (-0500)
Subject: kv/KeyValueDB: return const char* from MergeOperator::name()
X-Git-Tag: v13.2.2~54^2
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=refs%2Fpull%2F23865%2Fhead;p=ceph.git

kv/KeyValueDB: return const char* from MergeOperator::name()

This avoids a c_str() on a temporary string later down the line, which
avoids a use-after-free.

Fixes: http://tracker.ceph.com/issues/26875
Signed-off-by: Sage Weil <sage@redhat.com>
(cherry picked from commit e9be5dabf256c18a5575d1394e481e4f21ece97d)
---

diff --git a/src/kv/KeyValueDB.h b/src/kv/KeyValueDB.h
index 50714d24713..b0b129dd87b 100644
--- a/src/kv/KeyValueDB.h
+++ b/src/kv/KeyValueDB.h
@@ -387,7 +387,7 @@ public:
       const char *rdata, size_t rlen,
       std::string *new_value) = 0;
     /// We use each operator name and each prefix to construct the overall RocksDB operator name for consistency check at open time.
-    virtual string name() const = 0;
+    virtual const char *name() const = 0;
 
     virtual ~MergeOperator() {}
   };
diff --git a/src/kv/RocksDBStore.cc b/src/kv/RocksDBStore.cc
index 7f72e23ed03..3be625d1c05 100644
--- a/src/kv/RocksDBStore.cc
+++ b/src/kv/RocksDBStore.cc
@@ -127,7 +127,7 @@ public:
   MergeOperatorLinker(const std::shared_ptr<KeyValueDB::MergeOperator> &o) : mop(o) {}
 
   const char *Name() const override {
-    return mop->name().c_str();
+    return mop->name();
   }
 
   bool Merge(const rocksdb::Slice& key,
diff --git a/src/os/bluestore/BitmapFreelistManager.cc b/src/os/bluestore/BitmapFreelistManager.cc
index 0017df01a8c..779c05608b6 100644
--- a/src/os/bluestore/BitmapFreelistManager.cc
+++ b/src/os/bluestore/BitmapFreelistManager.cc
@@ -35,7 +35,7 @@ struct XorMergeOperator : public KeyValueDB::MergeOperator {
   }
   // We use each operator name and each prefix to construct the
   // overall RocksDB operator name for consistency check at open time.
-  string name() const override {
+  const char *name() const override {
     return "bitwise_xor";
   }
 };
diff --git a/src/os/bluestore/BlueStore.cc b/src/os/bluestore/BlueStore.cc
index 1b06d4bbdc3..39d6316e1e3 100644
--- a/src/os/bluestore/BlueStore.cc
+++ b/src/os/bluestore/BlueStore.cc
@@ -558,7 +558,7 @@ struct Int64ArrayMergeOperator : public KeyValueDB::MergeOperator {
   }
   // We use each operator name and each prefix to construct the
   // overall RocksDB operator name for consistency check at open time.
-  string name() const override {
+  const char *name() const override {
     return "int64_array";
   }
 };
diff --git a/src/test/objectstore/test_kv.cc b/src/test/objectstore/test_kv.cc
index cf5948f8c13..1869e79b3c5 100644
--- a/src/test/objectstore/test_kv.cc
+++ b/src/test/objectstore/test_kv.cc
@@ -208,7 +208,7 @@ struct AppendMOP : public KeyValueDB::MergeOperator {
   }
   // We use each operator name and each prefix to construct the
   // overall RocksDB operator name for consistency check at open time.
-  string name() const override {
+  const char *name() const override {
     return "Append";
   }
 };