CVE-2026-53130 fs/omfs: reject s_sys_blocksize smaller than OMFS_DIR_START

In the Linux kernel, the following vulnerability has been resolved: fs/omfs: reject ssysblocksize smaller than OMFSDIRSTART omfsfillsuper rejects oversized ssysblocksize values PAGESIZE, but it does not reject values smaller than OMFSDIRSTART 0x1b8 = 440. Later, omfsmakeempty uses sbi-ssysblocksi...

CVE-2026-53130

The CVE-2026-53130 issue affects the Linux kernel OMFS code path (fs/omfs). A crafted filesystem image with s_sys_blocksize b_data + OMFS_DIR_START due to an unsigned underflow. The result can overwrite kernel memory far beyond the backing block buffer. The advisory notes a fix: add a lower-bound...