Cloudanix VulnDB

CVE-2025-38578

None

CVSS

—

EPSS

0.2%

Published

Aug 19, 2025

CISA due date

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Cloudanix analysis

Schedule a fix SSVC: Track

A flaw in Linux file system handling can let attackers crash computers or potentially take control during routine file operations.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Privilege Gain
Component
OS kernel
Class
Use After Free
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Use-after-free in f2fs_sync_inode_meta() during inode list manipulation in the Linux kernel f2fs writeback path, allowing access to a freed inode structure.

Why it matters to the business

Kernel instability, crashes, or potential privilege escalation on Linux systems using f2fs, increasing downtime and security risk for servers and embedded devices with moderate ecosystem prevalence.

How an attack unfolds

An attacker performs file lookups and writes to trigger inode allocation followed by freeing during concurrent writeback, leading to UAF when f2fs_update_inode calls list operations on the stale structure; similar patterns seen in related privilege escalation campaigns on container-optimized OS.

How to fix it

Upgrade affected Linux kernel packages to versions containing commit 37e78cad7e9e025e63bb35bc200f44637b009bb1; for Chainguard packages apply openjdk-17-openj9 updates to 0.53.0-r0 or later.

How to confirm the fix worked

Confirm kernel build includes the listed commit; reproduce syzkaller-style workloads targeting f2fs namei and writeback paths and verify absence of KASAN reports.

Typical attack path

  1. Perform vfs operations to allocate and lock an f2fs inode via f2fs_iget
  2. Trigger conditions that free the inode while it remains on internal lists
  3. Initiate writeback via wb_workfn that reaches f2fs_write_inode
  4. Execute f2fs_update_inode_page which calls f2fs_inode_synced and list_del on freed memory

How to detect it

Inspect kernel logs and dmesg for KASAN use-after-free reports in __list_del_entry_valid or f2fs_inode_synced during writeback; correlate with f2fs-related workqueue activity.

What your security team should do

  • Prioritize kernel upgrades within published remediation windows due to related active campaigns
  • Enable KASAN or similar memory debugging in test environments to validate patches
  • Monitor f2fs usage and consider filesystem alternatives on high-risk systems
  • Review container runtime configurations for exposure to similar kernel issues

The record

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid UAF in f2fs_sync_inode_meta() syzbot reported an UAF issue as below: [1] [2] [1] https://syzkaller.appspot.com/text?tag=CrashReport&x=16594c60580000 ================================================================== BUG: KASAN: use-after-free in __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62 Read of size 8 at addr ffff888100567dc8 by task kworker/u4:0/8 CPU: 1 PID: 8 Comm: kworker/u4:0 Tainted: G W 6.1.129-syzkaller-00017-g642656a36791 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0x158/0x4e0 mm/kasan/report.c:427 kasan_report+0x13c/0x170 mm/kasan/report.c:531 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351 __list_del_entry_valid+0xa6/0x130 lib/list_debug.c:62 __list_del_entry include/linux/list.h:134 [inline] list_del_init include/linux/list.h:206 [inline] f2fs_inode_synced+0x100/0x2e0 fs/f2fs/super.c:1553 f2fs_update_inode+0x72/0x1c40 fs/f2fs/inode.c:588 f2fs_update_inode_page+0x135/0x170 fs/f2fs/inode.c:706 f2fs_write_inode+0x416/0x790 fs/f2fs/inode.c:734 write_inode fs/fs-writeback.c:1460 [inline] __writeback_single_inode+0x4cf/0xb80 fs/fs-writeback.c:1677 writeback_sb_inodes+0xb32/0x1910 fs/fs-writeback.c:1903 __writeback_inodes_wb+0x118/0x3f0 fs/fs-writeback.c:1974 wb_writeback+0x3da/0xa00 fs/fs-writeback.c:2081 wb_check_background_flush fs/fs-writeback.c:2151 [inline] wb_do_writeback fs/fs-writeback.c:2239 [inline] wb_workfn+0xbba/0x1030 fs/fs-writeback.c:2266 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446 kthread+0x26d/0x300 kernel/kthread.c:386 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> Allocated by task 298: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:333 kasan_slab_alloc include/linux/kasan.h:202 [inline] slab_post_alloc_hook+0x53/0x2c0 mm/slab.h:768 slab_alloc_node mm/slub.c:3421 [inline] slab_alloc mm/slub.c:3431 [inline] __kmem_cache_alloc_lru mm/slub.c:3438 [inline] kmem_cache_alloc_lru+0x102/0x270 mm/slub.c:3454 alloc_inode_sb include/linux/fs.h:3255 [inline] f2fs_alloc_inode+0x2d/0x350 fs/f2fs/super.c:1437 alloc_inode fs/inode.c:261 [inline] iget_locked+0x18c/0x7e0 fs/inode.c:1373 f2fs_iget+0x55/0x4ca0 fs/f2fs/inode.c:486 f2fs_lookup+0x3c1/0xb50 fs/f2fs/namei.c:484 __lookup_slow+0x2b9/0x3e0 fs/namei.c:1689 lookup_slow+0x5a/0x80 fs/namei.c:1706 walk_component+0x2e7/0x410 fs/namei.c:1997 lookup_last fs/namei.c:2454 [inline] path_lookupat+0x16d/0x450 fs/namei.c:2478 filename_lookup+0x251/0x600 fs/namei.c:2507 vfs_statx+0x107/0x4b0 fs/stat.c:229 vfs_fstatat fs/stat.c:267 [inline] vfs_lstat include/linux/fs.h:3434 [inline] __do_sys_newlstat fs/stat.c:423 [inline] __se_sys_newlstat+0xda/0x7c0 fs/stat.c:417 __x64_sys_newlstat+0x5b/0x70 fs/stat.c:417 x64_sys_call+0x52/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:7 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0x80 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 0: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249 kasan_slab_free include/linux/kasan.h:178 [inline] slab_free_hook mm/slub.c:1745 [inline] slab_free_freelist_hook mm/slub.c:1771 [inline] slab_free mm/slub.c:3686 [inline] kmem_cache_free+0x ---truncated---

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux 0 No fix
Debian:12 linux 0 No fix
Debian:13 linux 0 No fix
Debian:14 linux 0 No fix
Debian:14 linux 0 6.16.3-1
Linux Kernel 4.8.0 5.4.297
Mageia:9 kernel 0 6.6.105-1.mga9
Mageia:9 kernel-linus 0 6.6.105-1.mga9
Mageia:9 kmod-virtualbox 0 7.1.10-10.mga9
Mageia:9 kmod-xtables-addons 0 3.24-86.mga9
Mageia:9 mageia-repos 0 9-4.mga9
Mageia:9 meta-task 0 9-4.mga9

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