Linux Kernel up to 6.19.3 gfs2_iomap_begin use after free

CVSS Meta Temp Score
CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.
Current Exploit Price (≈)
Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.
CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
7.7$5k-$25k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.19.3. It has been rated as critical. This issue affects the function gfs2_iomap_begin. This manipulation causes use after free. This vulnerability is registered as CVE-2026-45984. No exploit is available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 6.19.3 and classified as critical. Affected by this vulnerability is the function gfs2_iomap_begin. The manipulation with an unknown input leads to a use after free vulnerability. The CWE definition for the vulnerability is CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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().]

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-45984 since 05/13/2026. The exploitation appears to be easy. Technical details are known, but no exploit is available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 06/21/2026).

The vulnerability scanner Nessus provides a plugin with the ID 321697 (SUSE SLES16 Security Update : kernel (SUSE-SU-2026:22099-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.252, 5.15.202, 6.1.165, 6.6.128, 6.12.75, 6.18.14 or 6.19.4 eliminates this vulnerability. Applying the patch 1403989d1b502f4a2c0d0b42ccf1c25748442eff/1cae1bafdf9caa9b462b19af06b1a06902e4e142/764c3c84b5683e608f43735c803a5f415046686c/d87268326b277af3665237ac76a73dd9fa8e21b4/87d4954b5c59735a99ea98cb208d47130f6dce7d/6d76febba07c40bcf358f63216d36ea68cf1c215/815ddd27c0c7171a99fe802fdb19098ddef8b19d/faddeb848305e79db89ee0479bb0e33380656321 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (321697). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.9
VulDB Meta Temp Score: 7.7

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 7.8
CNA Vector (Linux): 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock
UnlockUnlockUnlockUnlockUnlockUnlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

0-DayUnlockUnlockUnlockUnlock
TodayUnlockUnlockUnlockUnlock

Nessus ID: 321697
Nessus Name: SUSE SLES16 Security Update : kernel (SUSE-SU-2026:22099-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.252/5.15.202/6.1.165/6.6.128/6.12.75/6.18.14/6.19.4
Patch: 1403989d1b502f4a2c0d0b42ccf1c25748442eff/1cae1bafdf9caa9b462b19af06b1a06902e4e142/764c3c84b5683e608f43735c803a5f415046686c/d87268326b277af3665237ac76a73dd9fa8e21b4/87d4954b5c59735a99ea98cb208d47130f6dce7d/6d76febba07c40bcf358f63216d36ea68cf1c215/815ddd27c0c7171a99fe802fdb19098ddef8b19d/faddeb848305e79db89ee0479bb0e33380656321

Timelineinfo

05/13/2026 CVE reserved
05/27/2026 +14 days Advisory disclosed
05/27/2026 +0 days VulDB entry created
06/21/2026 +25 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-45984 (🔒)
GCVE (CVE): GCVE-0-2026-45984
GCVE (VulDB): GCVE-100-366205

Entryinfo

Created: 05/27/2026 17:13
Updated: 06/21/2026 07:48
Changes: 05/27/2026 17:13 (58), 06/16/2026 10:28 (11), 06/21/2026 07:48 (2)
Complete: 🔍
Cache ID: 216::103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Discussion

No comments yet. Languages: en.

Please log in to comment.

Do you know our Splunk app?

Download it now for free!