Siemens RUGGEDCOM RST2428P (6GK6242-6PA00) — kwetsbaarheid CVE-2026-23238

In the Linux kernel, the following vulnerability has been resolved: romfs: check sb_set_blocksize() return value romfs_fill_super() ignores the return value of sb_set_blocksize(), which can fail if the requested block size is incompatible with the block device's configuration. This can be triggered by setting a loop device's block size larger than PAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs filesystem on that device. When sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the device has logical_block_size=32768, bdev_validate_blocksize() fails because the requested size is smaller than the device's logical block size. sb_set_blocksize() returns 0 (failure), but romfs ignores this and continues mounting. The superblock's block size remains at the device's logical block size (32768). Later, when sb_bread() attempts I/O with this oversized block size, it triggers a kernel BUG in folio_set_bh(): kernel BUG at fs/buffer.c:1582! BUG_ON(size > PAGE_SIZE); Fix by checking the return value of sb_set_blocksize() and failing the mount with -EINVAL if it returns 0.

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

• •Netwerktoegang tot het getroffen apparaat of segment is vereist.
• •Er zijn geen geldige inloggegevens nodig.
• •Geen gebruikersinteractie vereist.

• •Pas de laatste firmware- of software-update toe en valideer de integriteit ervan.
• •Beperk netwerktoegang tot het getroffen apparaat tot een dedicated OT-beheersegment.
• •Implementeer netwerksegmentatie conform zones en conduits (IEC 62443-3-2).
• •Monitor op afwijkend protocolverkeer via een OT-aware detectiesysteem.