CVE-2026-93268

About vulnerability

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 product:

AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS

Affected packages:

linux @ 5.10.259 (+12 more)

Live-patch status from KernelCare for each operating system.