fs: avoid repeated scans in evict_inodes()

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-98924
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-10-23 13:17:13 UTC
Updated2026-10-23 13:17:13 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: 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.

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected ac05fbb40062411ea1b722aa2cede7feaa94f1b4 e4f3e476cd4066a815ef68cd6caa1828b9c167d5 git Not specified
CNA Linux Linux affected ac05fbb40062411ea1b722aa2cede7feaa94f1b4 3cdc6e12ff79f0f8a3ba62d7e61474ae4b5e119a git Not specified
CNA Linux Linux affected ac05fbb40062411ea1b722aa2cede7feaa94f1b4 7459c021874246c196f397686e100702f059b9e7 git Not specified
CNA Linux Linux affected 4.3 Not specified
CNA Linux Linux unaffected 4.3 semver Not specified
CNA Linux Linux unaffected 6.18.55 6.18.* semver Not specified
CNA Linux Linux unaffected 7.2.9 7.2.* semver Not specified
CNA Linux Linux unaffected 7.3 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/7459c021874246c196f397686e100702f059b9e7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/3cdc6e12ff79f0f8a3ba62d7e61474ae4b5e119a 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/e4f3e476cd4066a815ef68cd6caa1828b9c167d5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report