Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
f2fs: compress: don’t allow unaligned truncation on released compress inode
f2fs image may be corrupted after below testcase:
- mkfs.f2fs -O extra_attr,compression -f /dev/vdb
- mount /dev/vdb /mnt/f2fs
- touch /mnt/f2fs/file
- f2fs_io setflags compression /mnt/f2fs/file
- dd if=/dev/zero of=/mnt/f2fs/file bs=4k count=4
- f2fs_io release_cblocks /mnt/f2fs/file
- truncate -s 8192 /mnt/f2fs/file
- umount /mnt/f2fs
- fsck.f2fs /dev/vdb
[ASSERT] (fsck_chk_inode_blk:1256) –> ino: 0x5 has i_blocks: 0x00000002, but has 0x3 blocks [FSCK] valid_block_count matching with CP [Fail] [0x4, 0x5] [FSCK] other corrupted bugs [Fail]
The reason is: partial truncation assume compressed inode has reserved blocks, after partial truncation, valid block count may change w/o .i_blocks and .total_valid_block_count update, result in corruption.
This patch only allow cluster size aligned truncation on released compress inode for fixing.
Details
- Affected product:
- AlmaLinux 9.2 ESU , TuxCare 9.6 ESU
- Affected packages:
- kernel @ 5.14.0 (+1 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 11 | Will Not Fix |
30 kernels
|
| Debian 11 cloud | Will Not Fix |
10 kernels
|
| Debian 12 | Planned | — |
| Proxmox VE 7 5.15 | Released |
47 kernels
|
| Ubuntu 20.04 HWE AWS | Released |
45 kernels
|
| Ubuntu 20.04 HWE Azure | Released |
28 kernels
|
| Ubuntu 22.04 | Released |
58 kernels
|
| Ubuntu 22.04 AWS | Released |
52 kernels
|
| Ubuntu 22.04 Azure | Released |
48 kernels
|
| Ubuntu 24.04 | Released |
7 kernels
|