CVE-2026-63796 ocfs2: reject oversized group bitmap descriptors

In the Linux kernel, the following vulnerability has been resolved: ocfs2: reject oversized group bitmap descriptors ocfs2validategdparent only bounds bgbits against the parent allocator's chain geometry. A malicious descriptor can still claim a bgsize/bgbits pair that exceeds the bitmap bytes th...

CVE-2026-63796

CVE-2026-63796 concerns the Linux kernel’s OCFS2 filesystem. The issue arises when a malicious group descriptor can claim a bg_size/bg_bits pair that exceeds the on-disk group bitmap capacity, allowing bitmap scans and bit updates to run past bg_bitmap. The fix adds a physical-capacity check (bas...