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().]

Project Subscriptions

Vendors Products
Linux Kernel Subscribe
Advisories
Source ID Title
Debian DLA Debian DLA DLA-4606-1 linux security update
Ubuntu USN Ubuntu USN USN-8492-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8492-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8497-1 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-8498-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8499-1 Linux kernel (Xilinx) vulnerabilities
Ubuntu USN Ubuntu USN USN-8492-3 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-8492-4 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-8492-5 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8576-2 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-8597-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8575-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8606-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8607-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8609-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8610-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8619-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-3 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8620-4 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-8668-1 Linux kernel (GCP) vulnerabilities
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

References
Link Providers
https://access.redhat.com/errata/RHSA-2026:27789 cve-icon
https://access.redhat.com/errata/RHSA-2026:33743 cve-icon
https://access.redhat.com/errata/RHSA-2026:35894 cve-icon
https://access.redhat.com/errata/RHSA-2026:36049 cve-icon
https://access.redhat.com/errata/RHSA-2026:36767 cve-icon
https://access.redhat.com/errata/RHSA-2026:38902 cve-icon
https://access.redhat.com/errata/RHSA-2026:51603 cve-icon
https://access.redhat.com/errata/RHSA-2026:51604 cve-icon
https://access.redhat.com/errata/RHSA-2026:55444 cve-icon
https://access.redhat.com/errata/RHSA-2026:59142 cve-icon
https://access.redhat.com/errata/RHSA-2026:59143 cve-icon
https://access.redhat.com/errata/RHSA-2026:59145 cve-icon
https://access.redhat.com/errata/RHSA-2026:59146 cve-icon
https://access.redhat.com/errata/RHSA-2026:59147 cve-icon
https://access.redhat.com/errata/RHSA-2026:59148 cve-icon
https://access.redhat.com/errata/RHSA-2026:59149 cve-icon
https://access.redhat.com/security/cve/CVE-2026-45984 cve-icon
https://bugzilla.redhat.com/show_bug.cgi?id=2481922 cve-icon
https://git.kernel.org/stable/c/1403989d1b502f4a2c0d0b42ccf1c25748442eff cve-icon cve-icon
https://git.kernel.org/stable/c/1cae1bafdf9caa9b462b19af06b1a06902e4e142 cve-icon cve-icon
https://git.kernel.org/stable/c/6d76febba07c40bcf358f63216d36ea68cf1c215 cve-icon cve-icon
https://git.kernel.org/stable/c/764c3c84b5683e608f43735c803a5f415046686c cve-icon cve-icon
https://git.kernel.org/stable/c/815ddd27c0c7171a99fe802fdb19098ddef8b19d cve-icon cve-icon
https://git.kernel.org/stable/c/87d4954b5c59735a99ea98cb208d47130f6dce7d cve-icon cve-icon
https://git.kernel.org/stable/c/d87268326b277af3665237ac76a73dd9fa8e21b4 cve-icon cve-icon
https://git.kernel.org/stable/c/faddeb848305e79db89ee0479bb0e33380656321 cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2026052739-CVE-2026-45984-107d@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2026-45984 cve-icon
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-45984.json cve-icon
https://www.cve.org/CVERecord?id=CVE-2026-45984 cve-icon
History

Tue, 25 Aug 2026 13:30:00 +0000


Mon, 17 Aug 2026 12:30:00 +0000

Type Values Removed Values Added
References

Tue, 16 Jun 2026 06:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Sat, 30 May 2026 11:00:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Thu, 28 May 2026 04:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Thu, 28 May 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-826
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Wed, 27 May 2026 17:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416

Wed, 27 May 2026 14:15:00 +0000

Type Values Removed Values Added
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().]
Title gfs2: Fix use-after-free in iomap inline data write path
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-25T12:05:56.726Z

Reserved: 2026-05-13T15:03:33.090Z

Link: CVE-2026-45984

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Modified

Published: 2026-05-27T14:17:15.640

Modified: 2026-08-25T13:19:14.290

Link: CVE-2026-45984

cve-icon Redhat

Severity : Important

Publid Date: 2026-05-27T00:00:00Z

Links: CVE-2026-45984 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-06-18T00:00:05Z

Weaknesses