CVE-2026-99204 Vulnerability Analysis & Exploit Details

CVE-2026-99204
Vulnerability Scoring

Analysis In Progress
Analysis In Progress

Attack Complexity Details

  • Attack Complexity:
    Attack Complexity Analysis In Progress
  • Attack Vector:
    Attack Vector Under Analysis
  • Privileges Required: None
    No authentication is required for exploitation.
  • Scope:
    Impact is confined to the initially vulnerable component.
  • User Interaction: None
    No user interaction is necessary for exploitation.

CVE-2026-99204 Details

Status: Received on 28 Oct 2026, 11:17 UTC

Published on: 28 Oct 2026, 11:17 UTC

CVSS Release:

CVE-2026-99204 Vulnerability Summary

CVE-2026-99204: In the Linux kernel, the following vulnerability has been resolved: ocfs2/dlm: Protect the recovery list during debugfs reads Recovery participant records must remain alive while debug_state_print() walks reco.node_data and formats their fields. The formatter holds dlm->spinlock, but the recovery participant list is protected by dlm_reco_state_lock. In particular, dlm_destroy_recovery_area() detaches the list under dlm_reco_state_lock and frees the detached records after releasing it. A concurrent debugfs open can therefore read freed memory. Protect the participant traversal and field reads in debug_state_print() with dlm_reco_state_lock, matching the existing list writers. This also serializes the traversal against list_add_tail() during recovery-area initialization. Make the existing lock available to the debug code through dlmcommon.h; the lock remains internal to the OCFS2 DLM module. Release dlm->spinlock after formatting the other domain state and before acquiring dlm_reco_state_lock, so the debug reader does not nest the two locks. Leave recovery list insertion, detachment and freeing unchanged. KASAN report as below: BUG: KASAN: slab-use-after-free in debug_state_open+0x1169/0x12d0 Read of size 4 at addr ffff88810662ef80 by task dlm-state-stres/896 CPU: 1 UID: 0 PID: 896 Comm: dlm-state-stres Not tainted 7.3.0-rc4-next-20260921-pmb-ocfs2-functional-v1+ #1 PREEMPT(lazy) Hardware name: QEMU Ubuntu 24.04 PC v2 (i440FX + PIIX, arch_caps fix, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x93/0xd0 print_report+0xce/0x630 ? debug_state_open+0x1169/0x12d0 ? srso_alias_return_thunk+0x5/0xfbef5 ? __virt_addr_valid+0x20e/0x420 ? debug_state_open+0x1169/0x12d0 kasan_report+0xe0/0x110 ? debug_state_open+0x1169/0x12d0 debug_state_open+0x1169/0x12d0 ? __pfx_debug_state_open+0x10/0x10 full_proxy_open_regular+0x193/0x310 do_dentry_open+0x595/0x12d0 ? __pfx_full_proxy_open_regular+0x10/0x10 vfs_open_consume+0xd1/0x400 ? srso_alias_return_thunk+0x5/0xfbef5 path_openat+0x18d0/0x2020 ? __pfx_path_openat+0x10/0x10 do_file_open+0x21e/0x470 ? __pfx_do_file_open+0x10/0x10 ? _raw_spin_unlock+0x23/0x40 ? srso_alias_return_thunk+0x5/0xfbef5 ? alloc_fd+0x3a6/0x6b0 do_sys_openat2+0xf4/0x1b0 ? __pfx_do_sys_openat2+0x10/0x10 ? srso_alias_return_thunk+0x5/0xfbef5 ? __fput+0x5b5/0xa60 __x64_sys_openat+0x136/0x1e0 ? __pfx___x64_sys_openat+0x10/0x10 do_syscall_64+0x114/0x620 entry_SYSCALL_64_after_hwframe+0x77/0x7f [Register dump omitted.] </TASK> Allocated by task 880: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 __kmalloc_cache_noprof+0x28d/0x610 dlm_remaster_locks+0x147/0x1d90 dlm_do_recovery+0xde1/0x1580 dlm_recovery_thread+0x109/0x300 kthread+0x351/0x460 ret_from_fork+0x659/0x940 ret_from_fork_asm+0x1a/0x30 Freed by task 880: kasan_save_stack+0x33/0x60 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x60 __kasan_slab_free+0x5f/0x80 kfree+0x308/0x580 dlm_destroy_recovery_area+0x285/0x460 dlm_remaster_locks+0x17c4/0x1d90 dlm_do_recovery+0xde1/0x1580 dlm_recovery_thread+0x109/0x300 kthread+0x351/0x460 ret_from_fork+0x659/0x940 ret_from_fork_asm+0x1a/0x30 The buggy address belongs to the object at ffff88810662ef80 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 0 bytes inside of freed 32-byte region [ffff88810662ef80, ffff88810662efa0) [Page and memory-state dumps omitted.]

Assessing the Risk of CVE-2026-99204

Access Complexity Graph

The exploitability of CVE-2026-99204 depends on two key factors: attack complexity (the level of effort required to execute an exploit) and privileges required (the access level an attacker needs).

Exploitability Analysis for CVE-2026-99204

No exploitability data is available for CVE-2026-99204.

Understanding AC and PR

A lower complexity and fewer privilege requirements make exploitation easier. Security teams should evaluate these aspects to determine the urgency of mitigation strategies, such as patch management and access control policies.

Attack Complexity (AC) measures the difficulty in executing an exploit. A high AC means that specific conditions must be met, making an attack more challenging, while a low AC means the vulnerability can be exploited with minimal effort.

Privileges Required (PR) determine the level of system access necessary for an attack. Vulnerabilities requiring no privileges are more accessible to attackers, whereas high privilege requirements limit exploitation to authorized users with elevated access.

CVSS Score Breakdown Chart

Above is the CVSS Sub-score Breakdown for CVE-2026-99204, illustrating how Base, Impact, and Exploitability factors combine to form the overall severity rating. A higher sub-score typically indicates a more severe or easier-to-exploit vulnerability.

CIA Impact Analysis

Below is the Impact Analysis for CVE-2026-99204, showing how Confidentiality, Integrity, and Availability might be affected if the vulnerability is exploited. Higher values usually signal greater potential damage.

  • Confidentiality: None
    CVE-2026-99204 does not compromise confidentiality.
  • Integrity: None
    CVE-2026-99204 does not impact data integrity.
  • Availability: None
    CVE-2026-99204 does not affect system availability.

CVE-2026-99204 References

External References

CWE Common Weakness Enumeration

Unknown

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