Overview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 11 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU
- Affected packages:
- linux @ 5.10.259 (+7 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 13 | Released |
17 kernels
|