romfs: check sb_set_blocksize() return value (Linux Linux)

CVE-2026-23238
MEDIUM 5.5

At a glance

Source
NVD
EPSS
EPSS 0.20 % · percentile 10 ()
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Modified

Description

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.

Weaknesses (CWE)

  • CWE-617 — Reachable Assertion

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD · nvd@nist.gov (Primary)

European references

CERT-FR advisories

Affected configurations (NVD CPE)

Affected products

ProductVersions
Linux · Linuxaffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < a381f0f61b35c8894b0bd0d6acef2d8f9b08b244 ; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < f2521ab1f63a8c244f06a080319e5ff9a2e1bd95 ; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 2c5829cd8fbbc91568c520b666898f57cdcb8cf6 ; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < cbd9931e6456822067725354d83446c5bb813030 ; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 9b203b8ddd7359270e8a694d0584743555128e2c ; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 < 4b71ad7676564a94ec5f7d18298f51e8ae53db73
Linux · Linuxaffected 2.6.12 ; unaffected 0 < 2.6.12 ; unaffected 5.10.251 ≤ 5.10.* ; unaffected 5.15.201 ≤ 5.15.* ; unaffected 6.1.164 ≤ 6.1.* ; unaffected 6.6.127 ≤ 6.6.*

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST — attribution requested
ENISA EUVDENISA — reproduction authorised, source acknowledged
CERT-FR (ANSSI)Licence Ouverte / Etalab 2.0
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain — this product uses data from the NVD API but is not endorsed or certified by the NVD