In the Linux kernel, the following vulnerability has been resolved: ocfs2: clear extent cache after moving/defragmenting extents The extent map cache can become stale when extents are moved or defragmented, causing subsequent operations to see outdated extent flags. This triggers a BUGON in ocfs2refcountcalcowclusters(). The problem occurs when: 1. copyfilerange() creates a reflinked extent with OCFS2EXTREFCOUNTED 2. ioctl(FITRIM) triggers ocfs2moveextents() 3. _ocfs2moveextentsrange() reads and caches the extent (flags=0x2) 4. ocfs2moveextent()/ocfs2defragextent() calls _ocfs2moveextent() which clears OCFS2EXTREFCOUNTED flag on disk (flags=0x0) 5. The extent map cache is not invalidated after the move 6. Later write() operations read stale cached flags (0x2) but disk has updated flags (0x0), causing a mismatch 7. BUGON(!(rec->eflags & OCFS2EXTREFCOUNTED)) triggers Fix by clearing the extent map cache after each extent move/defrag operation in _ocfs2moveextentsrange(). This ensures subsequent operations read fresh extent data from disk.