CVE-2026-46159
btrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak
MEDIUM 4.7
At a glance
- Source
- NVD
- EPSS
- EPSS 0.10 % · percentile 1 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: fix btrfs_ioctl_space_info() slot_count TOCTOU which can lead to info-leak btrfs_ioctl_space_info() has a TOCTOU race between two passes over the block group RAID type lists. The first pass counts entries to determine the allocation size, then the second pass fills the buffer. The groups_sem rwlock is released between passes, allowing concurrent block group removal to reduce the entry count. When the second pass fills fewer entries than the first pass counted, copy_to_user() copies the full alloc_size bytes including trailing uninitialized kmalloc bytes to userspace. Fix by copying only total_spaces entries (the actually-filled count from the second pass) instead of alloc_size bytes, and switch to kzalloc so any future copy size mismatch cannot leak heap data.
Weaknesses (CWE)
- CWE-367 — TOCTOU Race Condition
References
- https://git.kernel.org/stable/c/f407aad350bdea4db300c47433573b7a41630d33
- https://git.kernel.org/stable/c/d8224b1be6627c6c3b204bfb264508d27c65ac44
- https://git.kernel.org/stable/c/d69a4a6813fdba7c4cc3695a7e843842b240790d
- https://git.kernel.org/stable/c/f5ee467b56764964027c361641f64953fc0f8f9a
- https://git.kernel.org/stable/c/4fdc6ee0802121d9cd96b8d085e589f51e5a4ec3
- https://git.kernel.org/stable/c/5d12e0ab009ade48c1bff9324fd9bea2c773d088
- https://git.kernel.org/stable/c/d09d67d5de577cedae3de9497dff217e0ac8b641
- https://git.kernel.org/stable/c/973e57c726c1f8e77259d1c8e519519f1e9aea77
- https://cert-portal.siemens.com/productcert/html/ssa-784472.html
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | MEDIUM 4.7 | CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H | NVD · nvd@nist.gov (Primary) |
European references
- ENISA EUVD · EUVD-2026-32786
- GCVE · GCVE-0-2026-46159
CERT-FR advisories
- CERTFR-2026-AVI-1385 — Multiples vulnérabilités dans les produits VMware · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1333 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1298 — Multiples vulnérabilités dans les produits Siemens · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1286 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1252 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1229 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1162 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1066 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0954 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0926 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0864 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0862 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0833 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0807 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0782 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0731 — Multiples vulnérabilités dans les produits Microsoft · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 2.6.34.1 < 6.6.140cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.90cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.32cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 7.0.7cpe:2.3:o:linux:linux_kernel:2.6.34:-:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:2.6.34:rc2:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:2.6.34:rc3:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:2.6.34:rc4:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:2.6.34:rc5:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:2.6.34:rc6:*:*:*:*:*:*cpe:2.3:o:linux:linux_kernel:2.6.34:rc7:*:*:*:*:*:*
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected 7fde62bffb576d384ea49a3aed3403d5609ee5bc < f407aad350bdea4db300c47433573b7a41630d33 ; affected 7fde62bffb576d384ea49a3aed3403d5609ee5bc < d8224b1be6627c6c3b204bfb264508d27c65ac44 ; affected 7fde62bffb576d384ea49a3aed3403d5609ee5bc < d69a4a6813fdba7c4cc3695a7e843842b240790d ; affected 7fde62bffb576d384ea49a3aed3403d5609ee5bc < f5ee467b56764964027c361641f64953fc0f8f9a ; affected 7fde62bffb576d384ea49a3aed3403d5609ee5bc < 4fdc6ee0802121d9cd96b8d085e589f51e5a4ec3 ; affected 7fde62bffb576d384ea49a3aed3403d5609ee5bc < 5d12e0ab009ade48c1bff9324fd9bea2c773d088 |
| Linux · Linux | affected 2.6.34 ; unaffected 0 < 2.6.34 ; unaffected 5.10.259 ≤ 5.10.* ; unaffected 5.15.210 ≤ 5.15.* ; unaffected 6.1.176 ≤ 6.1.* ; unaffected 6.6.140 ≤ 6.6.* |
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 |