CVE Catalog

CVE-2026-93268

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, ext4_try_to_expand_extra_isize() called during mount (!SB_ACTIVE) could move xattrs to external blocks and release ea_inodes via iput(), creating a circular lock dependency: s_writepages_rwsem -> jbd2_handle -> xattr_sem -> s_writepages_rwsem.

Risk Assessment

The circular lock dependency can cause a deadlock and hang the ext4 filesystem during mount, leading to system unavailability and potential data loss.

Recommendation

Update the Linux kernel to a version with the fix that skips extra isize expansion when the filesystem is not active (!SB_ACTIVE).

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS