CVE-2026-93269

In the Linux kernel, the following vulnerability has been resolved:

ext4: fix circular lock dependency in ext4_ext_migrate

Move iput(tmp_inode) after ext4_writepages_up_write() to avoid a

circular lock dependency between s_writepages_rwsem and sb_internal

(freeze protection).

The deadlock scenario:

CPU0 (EXT4_IOC_MIGRATE) CPU1 (orphan cleanup during mount)

---- ----

ext4_ext_migrate()

ext4_writepages_down_write()

s_writepages_rwsem (write)

ext4_evict_inode()

sb_start_intwrite() [sb_internal]

...

ext4_writepages()

s_writepages_rwsem (read) [BLOCKED]

iput(tmp_inode)

ext4_evict_inode()

sb_start_intwrite() [BLOCKED]

The tmp_inode is a temporary inode with nlink=0 created solely for

building the extent tree. Its eviction does not require

s_writepages_rwsem protection, so deferring iput() until after

releasing the rwsem is safe.