Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2 UFS ufs_fill_super null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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4.0$0-$5k0.19

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2 and classified as problematic. This affects the function ufs_fill_super of the component UFS. The manipulation results in null pointer dereference. This vulnerability is reported as CVE-2026-97927. The attack requires a local approach. No exploit exists. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.12.110/6.18.52/7.2.6/7.3-rc2. Affected is the function ufs_fill_super of the component UFS. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ufs: create the root dentry after loading cylinder metadata ufs_fill_super() installed sb->s_root before it loaded the cylinder group structures for a writable mount: sb->s_root = d_make_root(inode); ... if (!sb_rdonly(sb)) if (!ufs_read_cylinder_structures(sb)) goto failed; When ufs_read_cylinder_structures() failed, the error path freed the in-core superblock information and set sb->s_fs_info to NULL while sb->s_root stayed installed. get_tree_bdev() then reached deactivate_locked_super(), and because s_root was present, generic_shutdown_super() called sync_filesystem() and the put_super operation. Both dereference UFS_SB(sb), which is now NULL, so a mount that fails only while reading the cylinder groups oopses during teardown. A crafted image whose first cylinder group cannot be read reaches this path. Load the cylinder group metadata first and create the root dentry last, so the superblock is published to the VFS only once it is fully set up. ufs_setup_cstotal() and ufs_read_cylinder_structures() take only the super_block and do not use the root inode, so the reordering is safe.

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2026-97927 since 09/25/2026. The exploitability is told to be easy. Local access is required to approach this attack. Additional levels of successful authentication are required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit.

Upgrading to version 6.12.111, 6.18.53, 7.2.7 or 7.3-rc3 eliminates this vulnerability. Applying the patch a9804121d55aaa4319c1cac00b99794aa177dd6a/785e523b6c1931d802cab9f85912f3e6c7028af1/8173e051a8acbb4ae6547be0436727944119e0b5/55a4c98abb9694b067c6a031d11501f06b6b523c is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.2
VulDB Meta Temp Score: 4.0

VulDB Base Score: 4.2
VulDB Temp Score: 4.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.111/6.18.53/7.2.7/7.3-rc3
Patch: a9804121d55aaa4319c1cac00b99794aa177dd6a/785e523b6c1931d802cab9f85912f3e6c7028af1/8173e051a8acbb4ae6547be0436727944119e0b5/55a4c98abb9694b067c6a031d11501f06b6b523c

Timelineinfo

09/25/2026 Advisory disclosed
09/25/2026 +0 days CVE reserved
09/25/2026 +0 days VulDB entry created
09/25/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-97927 (🔒)
GCVE (CVE): GCVE-0-2026-97927
GCVE (VulDB): GCVE-100-410022

Entryinfo

Created: 09/25/2026 13:54
Changes: 09/25/2026 13:54 (59)
Complete: 🔍
Cache ID: 216::103

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