CVE-2025-38709
loop: Avoid updating block size under exclusive owner
At a glance
- Source
- NVD
- EPSS
- EPSS 0.15 % · percentile 4 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Analyzed
Description
In the Linux kernel, the following vulnerability has been resolved: loop: Avoid updating block size under exclusive owner Syzbot came up with a reproducer where a loop device block size is changed underneath a mounted filesystem. This causes a mismatch between the block device block size and the block size stored in the superblock causing confusion in various places such as fs/buffer.c. The particular issue triggered by syzbot was a warning in __getblk_slow() due to requested buffer size not matching block device block size. Fix the problem by getting exclusive hold of the loop device to change its block size. This fails if somebody (such as filesystem) has already an exclusive ownership of the block device and thus prevents modifying the loop device under some exclusive owner which doesn't expect it.
References
- https://git.kernel.org/stable/c/457d2c5e112fd08dc1039b1ae39a83ec1782360d
- https://git.kernel.org/stable/c/139a000d20f2f38ce34296feddd641d730fe1c08
- https://git.kernel.org/stable/c/b928438cc87c0bf7ae078e4b7b6e14261e84c5c5
- https://git.kernel.org/stable/c/5d67b30aefeb7a949040bbb1b4e3b84c5d29a624
- https://git.kernel.org/stable/c/7e49538288e523427beedd26993d446afef1a6fb
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2025-26760
- GCVE · GCVE-0-2025-38709
CERT-FR advisories
- CERTFR-2026-AVI-0602 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0421 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0397 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0371 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0331 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0326 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0316 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2025-AVI-1073 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0921 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2025-AVI-0895 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*< 6.6.109cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.43cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.15.11cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.16 < 6.16.2
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 89e4fdecb51cf5535867026274bc97de9480ade5 < 457d2c5e112fd08dc1039b1ae39a83ec1782360d ; affected 89e4fdecb51cf5535867026274bc97de9480ade5 < 139a000d20f2f38ce34296feddd641d730fe1c08 ; affected 89e4fdecb51cf5535867026274bc97de9480ade5 < b928438cc87c0bf7ae078e4b7b6e14261e84c5c5 ; affected 89e4fdecb51cf5535867026274bc97de9480ade5 < 5d67b30aefeb7a949040bbb1b4e3b84c5d29a624 ; affected 89e4fdecb51cf5535867026274bc97de9480ade5 < 7e49538288e523427beedd26993d446afef1a6fb |
| Linux · Linux | affected 4.14 ; unaffected 0 < 4.14 ; unaffected 6.6.109 ≤ 6.6.* ; unaffected 6.12.43 ≤ 6.12.* ; unaffected 6.15.11 ≤ 6.15.* ; unaffected 6.16.2 ≤ 6.16.* |
Sources
| Source | Licence |
|---|---|
| CVE List (CVEProject cvelistV5) | CVE Program Terms of Use |
| EPSS (FIRST.org) | FIRST — attribution requested |
| ENISA EUVD | ENISA — reproduction authorised, source acknowledged |
| CERT-FR (ANSSI) | Licence Ouverte / Etalab 2.0 |
| NVD (NIST) via fkie-cad/nvd-json-data-feeds | Public domain — this product uses data from the NVD API but is not endorsed or certified by the NVD |