CVE-2026-93268

Summary

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.

Affected Software

Weaknesses

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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