CVE-2026-45984

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Source
https://cve.org/CVERecord?id=CVE-2026-45984
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45984.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-45984
Downstream
Related
Published
2026-05-27T12:18:42Z
Modified
2026-09-06T03:31:01Z
Severity
  • 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
Summary
gfs2: Fix use-after-free in iomap inline data write path
Details

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().]

Database specific 
{
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/45xxx/CVE-2026-45984.json"
}
References

Affected packages

Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git

Affected ranges

Type
GIT
Repo
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Events
Introduced
d0a22a4b03b8475b7aa3fa41243c26c291407844
Fixed
1403989d1b502f4a2c0d0b42ccf1c25748442eff
Fixed
1cae1bafdf9caa9b462b19af06b1a06902e4e142
Fixed
764c3c84b5683e608f43735c803a5f415046686c
Fixed
d87268326b277af3665237ac76a73dd9fa8e21b4
Fixed
87d4954b5c59735a99ea98cb208d47130f6dce7d
Fixed
6d76febba07c40bcf358f63216d36ea68cf1c215
Fixed
815ddd27c0c7171a99fe802fdb19098ddef8b19d
Fixed
faddeb848305e79db89ee0479bb0e33380656321

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45984.json"

Linux / Kernel

Package

Name
Kernel

Affected ranges

Type
ECOSYSTEM
Events
Introduced
5.2.0
Fixed
5.10.252
Type
ECOSYSTEM
Events
Introduced
5.11.0
Fixed
5.15.202
Type
ECOSYSTEM
Events
Introduced
5.16.0
Fixed
6.1.165
Type
ECOSYSTEM
Events
Introduced
6.2.0
Fixed
6.6.128
Type
ECOSYSTEM
Events
Introduced
6.7.0
Fixed
6.12.75
Type
ECOSYSTEM
Events
Introduced
6.13.0
Fixed
6.18.14
Type
ECOSYSTEM
Events
Introduced
6.19.0
Fixed
6.19.4

Database specific

source 
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-45984.json"