CVE-2026-45984
gfs2: Fix use-after-free in iomap inline data write path
HIGH 7.8
At a glance
- Source
- NVD
- EPSS
- EPSS 0.18 % · percentile 8 ()
- State
- PUBLISHED
- Published
- Updated
- Assigner
- Linux
- NVD status
- Modified
Description
In the Linux kernel, the following vulnerability has been resolved: gfs2: Fix use-after-free in iomap inline data write path The inline data buffer head (dibh) is being released prematurely in gfs2_iomap_begin() via release_metapath() while iomap->inline_data still points to dibh->b_data. This causes a use-after-free when iomap_write_end_inline() later attempts to write to the inline data area. The bug sequence: 1. gfs2_iomap_begin() calls gfs2_meta_inode_buffer() to read inode metadata into dibh 2. Sets iomap->inline_data = dibh->b_data + sizeof(struct gfs2_dinode) 3. Calls release_metapath() which calls brelse(dibh), dropping refcount to 0 4. kswapd reclaims the page (~39ms later in the syzbot report) 5. iomap_write_end_inline() tries to memcpy() to iomap->inline_data 6. KASAN detects use-after-free write to freed memory Fix by storing dibh in iomap->private and incrementing its refcount with get_bh() in gfs2_iomap_begin(). The buffer is then properly released in gfs2_iomap_end() after the inline write completes, ensuring the page stays alive for the entire iomap operation. Note: A C reproducer is not available for this issue. The fix is based on analysis of the KASAN report and code review showing the buffer head is freed before use. [agruenba: Take buffer head reference in gfs2_iomap_begin() to avoid leaks in gfs2_iomap_get() and gfs2_iomap_alloc().]
Weaknesses (CWE)
References
- https://git.kernel.org/stable/c/1403989d1b502f4a2c0d0b42ccf1c25748442eff
- https://git.kernel.org/stable/c/1cae1bafdf9caa9b462b19af06b1a06902e4e142
- https://git.kernel.org/stable/c/764c3c84b5683e608f43735c803a5f415046686c
- https://git.kernel.org/stable/c/d87268326b277af3665237ac76a73dd9fa8e21b4
- https://git.kernel.org/stable/c/87d4954b5c59735a99ea98cb208d47130f6dce7d
- https://git.kernel.org/stable/c/6d76febba07c40bcf358f63216d36ea68cf1c215
- https://git.kernel.org/stable/c/815ddd27c0c7171a99fe802fdb19098ddef8b19d
- https://git.kernel.org/stable/c/faddeb848305e79db89ee0479bb0e33380656321
- https://access.redhat.com/security/cve/CVE-2026-45984
- https://bugzilla.redhat.com/show_bug.cgi?id=2481922
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45984.json
- https://access.redhat.com/errata/RHSA-2026:61692
- https://access.redhat.com/errata/RHSA-2026:63189
- https://access.redhat.com/errata/RHSA-2026:51603
- https://access.redhat.com/errata/RHSA-2026:36767
- https://access.redhat.com/errata/RHSA-2026:38902
- https://access.redhat.com/errata/RHSA-2026:27789
- https://access.redhat.com/errata/RHSA-2026:59143
- https://access.redhat.com/errata/RHSA-2026:33743
- https://access.redhat.com/errata/RHSA-2026:59146
- https://access.redhat.com/errata/RHSA-2026:35894
- https://access.redhat.com/errata/RHSA-2026:55444
- https://access.redhat.com/errata/RHSA-2026:59142
- https://access.redhat.com/errata/RHSA-2026:59147
- https://access.redhat.com/errata/RHSA-2026:59145
- https://access.redhat.com/errata/RHSA-2026:59148
- https://access.redhat.com/errata/RHSA-2026:59149
- https://access.redhat.com/errata/RHSA-2026:36049
- https://access.redhat.com/errata/RHSA-2026:51604
Scores
| Version | Score | Vector | Scored by |
|---|---|---|---|
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | Linux |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | redhat-SADP |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · 416baaa9-dc9f-4396-8d5f-8c081fb06d67 (Secondary) |
| CVSS 3.1 | HIGH 7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H | NVD · 0b0ca135-0b70-47e7-9f44-1890c2a1c46c (Secondary) |
European references
- ENISA EUVD · EUVD-2026-32269
- GCVE · GCVE-0-2026-45984
CERT-FR advisories
- CERTFR-2026-AVI-1287 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1229 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1118 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1094 — Multiples vulnérabilités dans les produits IBM · cert.ssi.gouv.fr
- CERTFR-2026-AVI-1093 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0985 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0983 — Multiples vulnérabilités dans le noyau Linux de Red Hat · 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-0899 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0864 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0863 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0861 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0833 — Multiples vulnérabilités dans le noyau Linux de SUSE · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0832 — Multiples vulnérabilités dans le noyau Linux de Red Hat · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0831 — Multiples vulnérabilités dans le noyau Linux d'Ubuntu · cert.ssi.gouv.fr
- CERTFR-2026-AVI-0808 — Multiples vulnérabilités dans le noyau Linux de Red Hat · 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-0696 — Multiples vulnérabilités dans le noyau Linux de Debian LTS · cert.ssi.gouv.fr
Affected configurations (NVD CPE)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.2 < 5.10.252cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.11 < 5.15.202cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 5.16 < 6.1.165cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.2 < 6.6.128cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.7 < 6.12.75cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.13 < 6.18.14cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*≥ 6.19 < 6.19.4
Affected products
| Product | Versions |
|---|---|
| Linux · Linux | affected d0a22a4b03b8475b7aa3fa41243c26c291407844 < 1403989d1b502f4a2c0d0b42ccf1c25748442eff ; affected d0a22a4b03b8475b7aa3fa41243c26c291407844 < 1cae1bafdf9caa9b462b19af06b1a06902e4e142 ; affected d0a22a4b03b8475b7aa3fa41243c26c291407844 < 764c3c84b5683e608f43735c803a5f415046686c ; affected d0a22a4b03b8475b7aa3fa41243c26c291407844 < d87268326b277af3665237ac76a73dd9fa8e21b4 ; affected d0a22a4b03b8475b7aa3fa41243c26c291407844 < 87d4954b5c59735a99ea98cb208d47130f6dce7d ; affected d0a22a4b03b8475b7aa3fa41243c26c291407844 < 6d76febba07c40bcf358f63216d36ea68cf1c215 |
| Linux · Linux | affected 5.2 ; unaffected 0 < 5.2 ; unaffected 5.10.252 ≤ 5.10.* ; unaffected 5.15.202 ≤ 5.15.* ; unaffected 6.1.165 ≤ 6.1.* ; unaffected 6.6.128 ≤ 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 |