Linux Distros Unpatched Vulnerability : CVE-2026-98924

critical Nessus Plugin ID 371504

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- fs: avoid repeated scans in evict_inodes() We observed hung tasks when users attempted to unmount a filesystem after its disk had been removed while still in use. During device removal, fs_bdev_mark_dead() calls evict_inodes() while holding s_umount. Each time evict_inodes() drops s_inode_list_lock to reschedule, it restarts the walk from the head of s_inodes. With many referenced inodes at the head of the list, these restarts repeatedly scan the same inodes without reclaiming them. This can keep s_umount held for a long time, blocking concurrent umount attempts and triggering hung-task reports. Keep the current inode, already marked I_FREEING, out of the disposal batch until s_inode_list_lock is reacquired. Resume the walk from this inode and dispose of it in a later batch or at the end of the walk. The zero-refcount and state checks under i_lock allow this walker to claim the inode by setting I_FREEING and removing it from the LRU. Other reclaimers skip the inode, leaving this walker responsible for eviction. Only evict() removes it from s_inodes, so keeping it out of the disposal batch ensures that it remains on the list while the lock is dropped. After reacquiring the lock, reading its current next pointer accounts for concurrent removal of following inodes. The existing inode lifetime rules prohibit acquiring a reference to an inode marked I_FREEING or I_WILL_FREE. __iget() requires its caller to hold i_lock and establish that taking a reference is valid. Inode lookup and igrab() check these flags under i_lock when acquiring a reference from zero. ihold() requires an existing reference, which would keep i_count nonzero and prevent this walker from claiming the inode. These rules already allow iput_final() and the inode shrinker to release i_lock after setting I_FREEING and before eviction completes. A temporary __iget() reference would also keep the inode on the list, but its release must preserve last-reference handling. Another user can acquire a reference, update lazy timestamps and drop its reference while the pin is held. If the pin becomes the last reference, dropping it with atomic_dec_and_test() and evicting directly bypasses iput()'s lazytime handling and can lose those timestamp updates. Releasing the pin with iput() preserves that handling, but does not guarantee eviction. fs_bdev_mark_dead() runs with SB_ACTIVE set, so iput() may retain the inode in cache, whereas evict_inodes() must evict eligible zero-reference inodes. The inode may also have been freed when iput() returns, so the walker cannot then use it to force eviction. Using I_FREEING preserves the existing eviction behavior without introducing an additional last-reference transition. The xfstests auto group passed on ext4 and XFS with known unrelated failures excluded. No new issues were observed, and the previously reproducible hung task no longer occurs with this patch.
(CVE-2026-98924)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

Plugin Details

Severity: Critical

ID: 371504

File Name: unpatched_CVE_2026_98924.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 10/23/2026

Updated: 10/23/2026

Supported Sensors: Agentless Assessment, Frictionless Assessment Agent, Nessus Agent, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.7

Percentile: 95.76

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P

CVSS Score Source: CVE-2026-98924

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:12.0, cpe:/o:debian:debian_linux:13.0, p-cpe:/a:debian:debian_linux:linux

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 10/23/2026

Reference Information

CVE: CVE-2026-98924

Detections

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