CVE-2026-93268
Received Received - Intake

Deadlock in Linux Kernel ext4 Filesystem

Publication date: 2026-09-24

Last updated on: 2026-09-24

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ext4: skip extra isize expansion during mount to prevent deadlock ext4_try_to_expand_extra_isize() is called from __ext4_mark_inode_dirty() while holding an active jbd2 handle. During mount (!SB_ACTIVE), the expand path may move xattrs to external blocks and release ea_inodes via iput(). When !SB_ACTIVE, iput() calls write_inode_now() which acquires s_writepages_rwsem, creating a circular lock dependency: s_writepages_rwsem --> jbd2_handle --> xattr_sem --> s_writepages_rwsem This can be triggered via: ext4_process_orphan() -> ext4_truncate() -> ext4_mark_inode_dirty() -> ext4_try_to_expand_extra_isize() or: ext4_evict_inode() -> ext4_mark_inode_dirty() -> ext4_try_to_expand_extra_isize() Skip expansion when !SB_ACTIVE. This is a minor loss of functionality (extra isize won't grow for these inodes during mount), which e2fsck can resolve later if needed.

CVSS Scores

EPSS Scores

Probability:
Percentile:

Meta Information

Published
2026-09-24
Last Modified
2026-09-24
Generated
2026-09-25
AI Q&A
2026-09-24
EPSS Evaluated
N/A
NVD
CVE-2026-93268
EUVD
EUVD-2026-86140

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

Helpful Resources

Exploitability

CWE
CWE Icon
KEV
KEV Icon
CWE ID Description
CWE-UNKNOWN

Attack-Flow Graph

AI Quick Actions

Instant insights powered by AI
Executive Summary

This is a Linux kernel vulnerability where a deadlock can occur during filesystem mount operations. The issue arises when the ext4 filesystem tries to expand inode size while handling orphaned or evicted inodes. This triggers a circular lock dependency involving the journaling system and writeback semaphores, potentially causing the system to hang.

Detection Guidance

This vulnerability is specific to the Linux kernel's ext4 filesystem and requires kernel-level inspection. Detection involves checking kernel logs for deadlock errors or verifying if your system is running a vulnerable kernel version. Use commands like 'uname -a' to check kernel version and 'dmesg | grep -i deadlock' to look for deadlock-related messages.

Impact Analysis

The vulnerability could cause system hangs or crashes during filesystem mount operations, particularly on ext4 filesystems. This may lead to data unavailability, system instability, or require a reboot to recover. The impact is most severe during system startup or when mounting filesystems.

Compliance Impact

This vulnerability does not directly affect compliance with GDPR, HIPAA, or similar standards. It is a Linux kernel deadlock issue during mount operations that could cause system instability but does not involve data breaches or unauthorized access.

Mitigation Strategies

Update your Linux kernel to the latest stable version that includes the fix for this vulnerability. Avoid mounting filesystems with the vulnerable kernel version. If immediate update is not possible, consider unmounting affected ext4 filesystems until patched.

Chat Assistant

Ask questions about this CVE
Hi! I’m here to help you understand CVE-2026-93268. Ask me anything about the vulnerability, its impact, or mitigation strategies.
0/70

EPSS Chart