Linux Kernel up to 6.18.51/7.2.5 ocfs2 fs/ocfs2/sysfile.c ocfs2_del_inode_from_orphan use after free

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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7.8$0-$5k0.00-

Summaryinfo

A vulnerability marked as very critical has been reported in Linux Kernel up to 6.18.51/7.2.5. The affected element is the function ocfs2_del_inode_from_orphan of the file fs/ocfs2/sysfile.c of the component ocfs2. This manipulation causes use after free. This vulnerability appears as CVE-2026-90204. The attack requires local access. There is no available exploit. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.18.51/7.2.5. It has been declared as very critical. Affected by this vulnerability is the function ocfs2_del_inode_from_orphan of the file fs/ocfs2/sysfile.c of the component ocfs2. 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: ocfs2: validate DIO orphan slot during inode read [BUG] A corrupted append-DIO dinode (high byte at offset 0xa1 corrupted from 0 to 1) can carry an i_dio_orphaned_slot outside the mounted filesystem slot range and trigger a use-after-free error: BUG: KASAN: slab-use-after-free in ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102 Read of size 8 at addr ffff88800b767c00 by task kworker/u8:3/85 Call Trace: ... ocfs2_get_system_file_inode+0x780/0x820 fs/ocfs2/sysfile.c:102 ocfs2_wipe_inode+0x292/0xf70 fs/ocfs2/inode.c:840 ocfs2_delete_inode fs/ocfs2/inode.c:1155 [inline] ocfs2_evict_inode+0x6c9/0x1170 fs/ocfs2/inode.c:1295 evict+0x38e/0x8f0 fs/inode.c:810 iput_final fs/inode.c:1914 [inline] iput fs/inode.c:1966 [inline] iput+0x55b/0x8b0 fs/inode.c:1926 ocfs2_recover_orphans+0x610/0xe40 fs/ocfs2/journal.c:2374 ocfs2_complete_recovery+0x5af/0xd00 fs/ocfs2/journal.c:1373 ... [CAUSE] ocfs2_del_inode_from_orphan() uses i_dio_orphaned_slot to index the slot-local system inode cache. The dinode validator does not check this active slot, so an out-of-range value produces an invalid cache entry pointer that is dereferenced as an inode pointer. [FIX] Reject an active i_dio_orphaned_slot outside the slot range during dinode validation, before DIO orphan recovery can consume it.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2026-90204 since 09/11/2026. The exploitation appears to be easy. An attack has to be approached locally. Additional levels of successful authentication are necessary for exploitation. Technical details are known, but no exploit is available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/17/2026).

Upgrading to version 6.18.52, 7.2.6 or 7.3-rc1 eliminates this vulnerability. Applying the patch e35fa6eb4d2a39f8049f62361a4b44930882b5f8/418e0ae42fa769d354b15e62c01a00413024755b/bb88131c9831075b8dc08cdd375743e5d44c7ca2 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: 8.2
VulDB Meta Temp Score: 7.8

VulDB Base Score: 8.2
VulDB Temp Score: 7.8
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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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: No

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 6.18.52/7.2.6/7.3-rc1
Patch: e35fa6eb4d2a39f8049f62361a4b44930882b5f8/418e0ae42fa769d354b15e62c01a00413024755b/bb88131c9831075b8dc08cdd375743e5d44c7ca2

Timelineinfo

09/11/2026 CVE reserved
09/17/2026 +6 days Advisory disclosed
09/17/2026 +0 days VulDB entry created
09/17/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90204 (🔒)
GCVE (CVE): GCVE-0-2026-90204
GCVE (VulDB): GCVE-100-406753

Entryinfo

Created: 09/17/2026 20:57
Changes: 09/17/2026 20:57 (60)
Complete: 🔍
Cache ID: 216::103

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