[graphics/digikam] core/utilities/geolocation: Fix map view crash with allocators enforcing sized deallocation

Git commit bf9c1416f274890ba82c6f7bbad29b7462283088 by Mikhail Hrechyn.
Committed on 22/07/2026 at 15:22.
Pushed by cgilles into branch 'master'.

Fix map view crash with allocators enforcing sized deallocation

AbstractMarkerTiler::Tile has a non-virtual destructor, but the tile
tree always deletes the ItemMarkerTiler::MyTile and
GPSMarkerTiler::MyTile subclass objects through Tile pointers (the
rootTile scoped pointer, the children loop in ~Tile() and
Tile::deleteChild()). The subclass destructors are therefore never
run, leaking markerIndices/imagesId, and the compiler emits C++14
sized deallocation with sizeof(Tile) while the allocation has the
size of the subclass. The glibc allocator ignores the size argument,
but allocators that enforce it, like hardened_malloc which secureblue
preloads into all Flatpak applications, abort with "fatal allocator
error: sized deallocation mismatch (small)" as soon as the map view
paints.

Commit 90daa0b725 (Coverity CR 1504108) tried to fix this by making
the destructor of the derived MyTile virtual, which gives MyTile a
vtable pointer while Tile stays non-polymorphic. The Tile subobject
then moves to a nonzero offset and deleting through a Tile pointer
frees an interior pointer, which is the unit test crash that led to
the revert in commit a0345e9209. The destructor must be virtual on
the base class instead: this way the tiles are destroyed and
deallocated completely and with the correct size everywhere.

BUG: 522748
FIXED-IN: 9.2.0

M  +14   -1    core/utilities/geolocation/geoiface/tiles/abstractmarkertiler.h
M  +2    -2    core/utilities/geolocation/geoiface/tiles/itemmarkertiler.cpp
M  +2    -5    core/utilities/geolocation/mapsearches/gpsmarkertiler.cpp

https://invent.kde.org/graphics/digikam/-/commit/bf9c1416f274890ba82c6f7bbad29b7462283088

diff --git a/core/utilities/geolocation/geoiface/tiles/abstractmarkertiler.h b/core/utilities/geolocation/geoiface/tiles/abstractmarkertiler.h
index 2e442e1bc1..64962f19ff 100644
--- a/core/utilities/geolocation/geoiface/tiles/abstractmarkertiler.h
+++ b/core/utilities/geolocation/geoiface/tiles/abstractmarkertiler.h
@@ -68,7 +68,20 @@ public:
     public:
 
         Tile() = default;
-        ~Tile();
+
+        /**
+         * @note The destructor must be virtual: tiles are created by the
+         * tileNew() factory of the subclasses and are always deleted
+         * through Tile pointers (rootTile, ~Tile(), deleteChild()).
+         * Making only the subclass destructor virtual moves the Tile
+         * subobject to a nonzero offset, so deleting through a Tile
+         * pointer frees an interior pointer and crashes. With no virtual
+         * destructor at all the subclass destructor is skipped (leaking
+         * its members) and C++14 sized deallocation passes the wrong
+         * size, which aborts under allocators enforcing it, like
+         * hardened_malloc. See bug #522748.
+         */
+        virtual ~Tile();
 
     public:
 
diff --git a/core/utilities/geolocation/geoiface/tiles/itemmarkertiler.cpp b/core/utilities/geolocation/geoiface/tiles/itemmarkertiler.cpp
index 63f1c0152c..672b50e103 100644
--- a/core/utilities/geolocation/geoiface/tiles/itemmarkertiler.cpp
+++ b/core/utilities/geolocation/geoiface/tiles/itemmarkertiler.cpp
@@ -28,8 +28,8 @@ class Q_DECL_HIDDEN ItemMarkerTiler::MyTile : public Tile
 {
 public:
 
-    MyTile()          = default;
-    ~MyTile()         = default;      // No virtual destructor else crash at in unit-test.
+    MyTile()           = default;
+    ~MyTile() override = default;
 
     void removeMarkerIndexOrInvalidIndex(const QModelIndex& indexToRemove);
 
diff --git a/core/utilities/geolocation/mapsearches/gpsmarkertiler.cpp b/core/utilities/geolocation/mapsearches/gpsmarkertiler.cpp
index 63f3c31066..c75dabfc8a 100644
--- a/core/utilities/geolocation/mapsearches/gpsmarkertiler.cpp
+++ b/core/utilities/geolocation/mapsearches/gpsmarkertiler.cpp
@@ -50,13 +50,10 @@ class Q_DECL_HIDDEN GPSMarkerTiler::MyTile : public Tile
 {
 public:
 
-    MyTile()  = default;
+    MyTile()           = default;
+    ~MyTile() override = default;
 
     QList<qlonglong> imagesId;
-
-private:
-
-    ~MyTile() = delete;
 };
 
 class Q_DECL_HIDDEN GPSMarkerTiler::Private