Cloudanix VulnDB

CVE-2024-56744

Medium · 5.5

CVSS

5.5

EPSS

0.2%

Published

Dec 29, 2024

CISA due date

—

Cloudanix analysis

Next patch cycle SSVC: Track

A flaw in the Linux file system code can cause the computer to freeze when handling certain file operations under heavy memory use.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Moderate
Impact
Denial Of Service
Component
OS kernel
Class
Race Condition
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Circular locking dependency between sb_lock and sb_internal during f2fs inode eviction and stop-reason recording under memory pressure leads to deadlock.

Why it matters to the business

Linux systems using f2fs may experience kernel hangs or crashes during normal file operations and memory reclamation, causing unplanned downtime and potential data unavailability.

How an attack unfolds

An attacker or automated workload triggers inode eviction while f2fs is committing superblock metadata, reversing the expected lock acquisition order and deadlocking the system; no widespread exploitation observed despite mentions of kernel-related campaigns.

How to fix it

Update the Linux kernel to a version containing commit ecf4e6782b01fd578b565b3dd2be7bb0ac91082e or later; rebuild and reboot affected systems.

How to confirm the fix worked

Confirm the presence of the fix commit in the running kernel source; monitor for absence of the circular locking warning in kernel logs after upgrade.

Typical attack path

  1. Trigger memory pressure to activate kswapd and inode pruning
  2. Cause f2fs inode eviction which acquires sb_internal
  3. Simultaneously invoke f2fs_record_stop_reason which attempts sb_lock
  4. Induce lock-order inversion resulting in deadlock

How to detect it

Search kernel logs for lockdep circular dependency warnings involving sb_lock and sb_internal during f2fs operations or kswapd activity.

What your security team should do

  • Prioritize kernel updates on all f2fs deployments within maintenance windows
  • Test f2fs workloads under memory pressure post-upgrade
  • Review monitoring for f2fs-related lockdep warnings

The record

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid potential deadlock in f2fs_record_stop_reason() syzbot reports deadlock issue of f2fs as below: ====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc3-syzkaller-00087-gc964ced77262 #0 Not tainted ------------------------------------------------------ kswapd0/79 is trying to acquire lock: ffff888011824088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2199 [inline] ffff888011824088 (&sbi->sb_lock){++++}-{3:3}, at: f2fs_record_stop_reason+0x52/0x1d0 fs/f2fs/super.c:4068 but task is already holding lock: ffff88804bd92610 (sb_internal#2){.+.+}-{0:0}, at: f2fs_evict_inode+0x662/0x15c0 fs/f2fs/inode.c:842 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (sb_internal#2){.+.+}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1716 [inline] sb_start_intwrite+0x4d/0x1c0 include/linux/fs.h:1899 f2fs_evict_inode+0x662/0x15c0 fs/f2fs/inode.c:842 evict+0x4e8/0x9b0 fs/inode.c:725 f2fs_evict_inode+0x1a4/0x15c0 fs/f2fs/inode.c:807 evict+0x4e8/0x9b0 fs/inode.c:725 dispose_list fs/inode.c:774 [inline] prune_icache_sb+0x239/0x2f0 fs/inode.c:963 super_cache_scan+0x38c/0x4b0 fs/super.c:223 do_shrink_slab+0x701/0x1160 mm/shrinker.c:435 shrink_slab+0x1093/0x14d0 mm/shrinker.c:662 shrink_one+0x43b/0x850 mm/vmscan.c:4818 shrink_many mm/vmscan.c:4879 [inline] lru_gen_shrink_node mm/vmscan.c:4957 [inline] shrink_node+0x3799/0x3de0 mm/vmscan.c:5937 kswapd_shrink_node mm/vmscan.c:6765 [inline] balance_pgdat mm/vmscan.c:6957 [inline] kswapd+0x1ca3/0x3700 mm/vmscan.c:7226 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #1 (fs_reclaim){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __fs_reclaim_acquire mm/page_alloc.c:3834 [inline] fs_reclaim_acquire+0x88/0x130 mm/page_alloc.c:3848 might_alloc include/linux/sched/mm.h:318 [inline] prepare_alloc_pages+0x147/0x5b0 mm/page_alloc.c:4493 __alloc_pages_noprof+0x16f/0x710 mm/page_alloc.c:4722 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_pages_noprof mm/mempolicy.c:2345 [inline] folio_alloc_noprof+0x128/0x180 mm/mempolicy.c:2352 filemap_alloc_folio_noprof+0xdf/0x500 mm/filemap.c:1010 do_read_cache_folio+0x2eb/0x850 mm/filemap.c:3787 read_mapping_folio include/linux/pagemap.h:1011 [inline] f2fs_commit_super+0x3c0/0x7d0 fs/f2fs/super.c:4032 f2fs_record_stop_reason+0x13b/0x1d0 fs/f2fs/super.c:4079 f2fs_handle_critical_error+0x2ac/0x5c0 fs/f2fs/super.c:4174 f2fs_write_inode+0x35f/0x4d0 fs/f2fs/inode.c:785 write_inode fs/fs-writeback.c:1503 [inline] __writeback_single_inode+0x711/0x10d0 fs/fs-writeback.c:1723 writeback_single_inode+0x1f3/0x660 fs/fs-writeback.c:1779 sync_inode_metadata+0xc4/0x120 fs/fs-writeback.c:2849 f2fs_release_file+0xa8/0x100 fs/f2fs/file.c:1941 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x168/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f ---truncated---

Affected packages

Ecosystem Package Introduced Fixed
Debian:13 linux 0 6.12.3-1
Linux Kernel 6.5.0 6.6.64
Ubuntu:16.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-aws-5.0 0 No fix
Ubuntu:18.04:LTS linux-aws-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure 0 No fix
Ubuntu:18.04:LTS linux-azure-5.3 0 No fix
Ubuntu:18.04:LTS linux-azure-edge 0 No fix
Ubuntu:18.04:LTS linux-gcp 0 No fix
Ubuntu:18.04:LTS linux-gcp-5.3 0 No fix
Ubuntu:18.04:LTS linux-gke-4.15 0 No fix
Ubuntu:18.04:LTS linux-gke-5.4 0 No fix
Ubuntu:18.04:LTS linux-gkeop-5.4 0 No fix
Ubuntu:18.04:LTS linux-hwe 0 No fix
Ubuntu:18.04:LTS linux-hwe-edge 0 No fix
Ubuntu:18.04:LTS linux-oem 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.0 0 No fix
Ubuntu:18.04:LTS linux-oracle-5.3 0 No fix
Ubuntu:20.04:LTS linux 0 No fix
Ubuntu:20.04:LTS linux-aws 0 No fix
Ubuntu:20.04:LTS linux-aws-5.11 0 No fix
Ubuntu:20.04:LTS linux-aws-5.13 0 No fix
Ubuntu:20.04:LTS linux-aws-5.15 0 No fix
Ubuntu:20.04:LTS linux-aws-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure 0 No fix
Ubuntu:20.04:LTS linux-azure-5.11 0 No fix
Ubuntu:20.04:LTS linux-azure-5.13 0 No fix
Ubuntu:20.04:LTS linux-azure-5.15 0 No fix
Ubuntu:20.04:LTS linux-azure-5.8 0 No fix
Ubuntu:20.04:LTS linux-azure-fde 0 No fix
Ubuntu:20.04:LTS linux-azure-fde-5.15 0 No fix
Ubuntu:20.04:LTS linux-bluefield 0 No fix
Ubuntu:20.04:LTS linux-gcp 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.11 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.13 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.15 0 No fix
Ubuntu:20.04:LTS linux-gcp-5.8 0 No fix
Ubuntu:20.04:LTS linux-gke 0 No fix
Ubuntu:20.04:LTS linux-gke-5.15 0 No fix
Ubuntu:20.04:LTS linux-gkeop 0 No fix
Ubuntu:20.04:LTS linux-gkeop-5.15 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.11 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.13 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.15 0 No fix
Ubuntu:20.04:LTS linux-hwe-5.8 0 No fix
Ubuntu:20.04:LTS linux-ibm 0 No fix
Ubuntu:20.04:LTS linux-ibm-5.15 0 No fix
Ubuntu:20.04:LTS linux-intel-5.13 0 No fix
Ubuntu:20.04:LTS linux-intel-iotg-5.15 0 No fix
Ubuntu:20.04:LTS linux-iot 0 No fix
Ubuntu:20.04:LTS linux-kvm 0 No fix
Ubuntu:20.04:LTS linux-lowlatency-hwe-5.15 0 No fix
Ubuntu:20.04:LTS linux-oem-5.10 0 No fix
Ubuntu:20.04:LTS linux-oem-5.13 0 No fix
Ubuntu:20.04:LTS linux-oem-5.14 0 No fix
Ubuntu:20.04:LTS linux-oem-5.6 0 No fix
Ubuntu:20.04:LTS linux-oracle 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.11 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.13 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.15 0 No fix
Ubuntu:20.04:LTS linux-oracle-5.8 0 No fix
Ubuntu:20.04:LTS linux-raspi 0 No fix
Ubuntu:20.04:LTS linux-raspi2 0 No fix
Ubuntu:20.04:LTS linux-riscv 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.11 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.15 0 No fix
Ubuntu:20.04:LTS linux-riscv-5.8 0 No fix
Ubuntu:20.04:LTS linux-xilinx-zynqmp 0 No fix
Ubuntu:22.04:LTS linux 0 No fix
Ubuntu:22.04:LTS linux-allwinner-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws 0 No fix
Ubuntu:22.04:LTS linux-aws-5.19 0 No fix
Ubuntu:22.04:LTS linux-aws-6.2 0 No fix
Ubuntu:22.04:LTS linux-aws-6.5 0 No fix
Ubuntu:22.04:LTS linux-aws-6.8 0 No fix
Ubuntu:22.04:LTS linux-aws-6.8 0 6.8.0-1027.29~22.04.1
Ubuntu:22.04:LTS linux-azure 0 No fix
Ubuntu:22.04:LTS linux-azure-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-6.2 0 No fix
Ubuntu:22.04:LTS linux-azure-6.5 0 No fix
Ubuntu:22.04:LTS linux-azure-6.8 0 No fix
Ubuntu:22.04:LTS linux-azure-6.8 0 6.8.0-1027.32~22.04.1
Ubuntu:22.04:LTS linux-azure-fde 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-5.19 0 No fix
Ubuntu:22.04:LTS linux-azure-fde-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp 0 No fix
Ubuntu:22.04:LTS linux-gcp-5.19 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.2 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.5 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.8 0 No fix
Ubuntu:22.04:LTS linux-gcp-6.8 0 6.8.0-1028.30~22.04.1
Ubuntu:22.04:LTS linux-gke 0 No fix
Ubuntu:22.04:LTS linux-gkeop 0 No fix
Ubuntu:22.04:LTS linux-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 No fix
Ubuntu:22.04:LTS linux-hwe-6.8 0 6.8.0-58.60~22.04.1
Ubuntu:22.04:LTS linux-ibm 0 No fix
Ubuntu:22.04:LTS linux-ibm-6.8 0 6.8.0-1024.24~22.04.1
Ubuntu:22.04:LTS linux-intel-iot-realtime 0 No fix
Ubuntu:22.04:LTS linux-intel-iotg 0 No fix
Ubuntu:22.04:LTS linux-kvm 0 No fix
Ubuntu:22.04:LTS linux-lowlatency 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-5.19 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.2 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.5 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 No fix
Ubuntu:22.04:LTS linux-lowlatency-hwe-6.8 0 6.8.0-58.60.1~22.04.1
Ubuntu:22.04:LTS linux-nvidia 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.2 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.5 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.8 0 No fix
Ubuntu:22.04:LTS linux-nvidia-6.8 0 6.8.0-1026.29~22.04.1
Ubuntu:22.04:LTS linux-nvidia-tegra 0 No fix
Ubuntu:22.04:LTS linux-nvidia-tegra-igx 0 No fix
Ubuntu:22.04:LTS linux-oem-5.17 0 No fix
Ubuntu:22.04:LTS linux-oem-6.0 0 No fix
Ubuntu:22.04:LTS linux-oem-6.1 0 No fix
Ubuntu:22.04:LTS linux-oem-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle 0 No fix
Ubuntu:22.04:LTS linux-oracle-6.5 0 No fix
Ubuntu:22.04:LTS linux-oracle-6.8 0 No fix
Ubuntu:22.04:LTS linux-oracle-6.8 0 6.8.0-1024.25~22.04.1
Ubuntu:22.04:LTS linux-raspi 0 No fix
Ubuntu:22.04:LTS linux-realtime 0 No fix
Ubuntu:22.04:LTS linux-riscv 0 No fix
Ubuntu:22.04:LTS linux-riscv-5.19 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.5 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.8 0 No fix
Ubuntu:22.04:LTS linux-riscv-6.8 0 6.8.0-58.60.1~22.04.1
Ubuntu:22.04:LTS linux-starfive-5.19 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.2 0 No fix
Ubuntu:22.04:LTS linux-starfive-6.5 0 No fix
Ubuntu:22.04:LTS linux-xilinx-zynqmp 0 No fix
Ubuntu:22.04:LTS:for:NVIDIA:BlueField linux-bluefield 0 No fix
Ubuntu:24.04:LTS linux 0 No fix
Ubuntu:24.04:LTS linux 0 6.8.0-58.60
Ubuntu:24.04:LTS linux-aws 0 No fix
Ubuntu:24.04:LTS linux-aws 0 6.8.0-1027.29
Ubuntu:24.04:LTS linux-azure 0 No fix
Ubuntu:24.04:LTS linux-azure 0 6.8.0-1027.32
Ubuntu:24.04:LTS linux-azure-6.11 0 6.11.0-1012.12~24.04.1
Ubuntu:24.04:LTS linux-azure-fde 0 No fix
Ubuntu:24.04:LTS linux-azure-nvidia 0 6.8.0-1014.15
Ubuntu:24.04:LTS linux-gcp 0 No fix
Ubuntu:24.04:LTS linux-gcp 0 6.8.0-1028.30
Ubuntu:24.04:LTS linux-gcp-6.11 0 6.11.0-1011.11~24.04.1
Ubuntu:24.04:LTS linux-gke 0 No fix
Ubuntu:24.04:LTS linux-gke 0 6.8.0-1023.27
Ubuntu:24.04:LTS linux-gkeop 0 No fix
Ubuntu:24.04:LTS linux-gkeop 0 6.8.0-1010.12
Ubuntu:24.04:LTS linux-ibm 0 No fix
Ubuntu:24.04:LTS linux-ibm 0 6.8.0-1024.24
Ubuntu:24.04:LTS linux-intel 0 No fix
Ubuntu:24.04:LTS linux-lowlatency 0 No fix
Ubuntu:24.04:LTS linux-lowlatency 0 6.8.0-58.60.1
Ubuntu:24.04:LTS linux-nvidia 0 No fix
Ubuntu:24.04:LTS linux-nvidia 0 6.8.0-1026.29
Ubuntu:24.04:LTS linux-nvidia-6.11 0 6.11.0-1007.7
Ubuntu:24.04:LTS linux-nvidia-lowlatency 0 No fix
Ubuntu:24.04:LTS linux-nvidia-lowlatency 0 6.8.0-1026.29.1
Ubuntu:24.04:LTS linux-nvidia-tegra 0 No fix
Ubuntu:24.04:LTS linux-nvidia-tegra 0 6.8.0-1008.8
Ubuntu:24.04:LTS linux-oem-6.11 0 No fix
Ubuntu:24.04:LTS linux-oem-6.11 0 6.11.0-1015.15
Ubuntu:24.04:LTS linux-oem-6.8 0 No fix
Ubuntu:24.04:LTS linux-oem-6.8 0 6.8.0-1026.26
Ubuntu:24.04:LTS linux-oracle 0 No fix
Ubuntu:24.04:LTS linux-oracle 0 6.8.0-1024.25
Ubuntu:24.04:LTS linux-raspi 0 No fix
Ubuntu:24.04:LTS linux-raspi 0 6.8.0-1028.32
Ubuntu:24.04:LTS linux-raspi-realtime 0 No fix
Ubuntu:24.04:LTS linux-realtime 0 No fix
Ubuntu:24.04:LTS linux-riscv 0 No fix
Ubuntu:24.04:LTS linux-riscv 0 6.8.0-58.60.1
Ubuntu:24.04:LTS linux-xilinx 0 6.8.0-1017.18
Ubuntu:24.10 linux 0 No fix
Ubuntu:24.10 linux 0 6.11.0-18.18
Ubuntu:24.10 linux-aws 0 No fix
Ubuntu:24.10 linux-aws 0 6.11.0-1009.10
Ubuntu:24.10 linux-azure 0 No fix
Ubuntu:24.10 linux-azure 0 6.11.0-1009.9
Ubuntu:24.10 linux-gcp 0 No fix
Ubuntu:24.10 linux-gcp 0 6.11.0-1009.9
Ubuntu:24.10 linux-lowlatency 0 No fix
Ubuntu:24.10 linux-lowlatency 0 6.11.0-1010.11
Ubuntu:24.10 linux-oracle 0 No fix
Ubuntu:24.10 linux-oracle 0 6.11.0-1011.12
Ubuntu:24.10 linux-raspi 0 No fix
Ubuntu:24.10 linux-raspi 0 6.11.0-1008.8
Ubuntu:24.10 linux-realtime 0 No fix
Ubuntu:24.10 linux-realtime 0 6.11.0-1005.5
Ubuntu:24.10 linux-riscv 0 No fix
Ubuntu:25.04 linux-azure-fde 0 No fix
Ubuntu:Nvidia-BlueField:22.04:LTS linux-bluefield 0 No fix
Ubuntu:Pro:14.04:LTS linux 0 No fix
Ubuntu:Pro:14.04:LTS linux-aws 0 No fix
Ubuntu:Pro:14.04:LTS linux-azure 0 No fix
Ubuntu:Pro:14.04:LTS linux-lts-xenial 0 No fix

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