---
id: CVE-2022-50009
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data

  There is issue as follows when test f2fs atomic write:
  F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th supe…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data

  There is issue as follows when test f2fs atomic write:
  F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th supe…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: linux
product: linux_kernel
affected:
  - 'linux_kernel >= 3.8, < 5.18.18'
  - 'linux_kernel >= 5.19, < 5.19.4'
patched:
  - linux_kernel 5.19.4
published: '2025-06-18'
updated: '2026-08-15'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2022-50009'
references:
  - url: 'https://git.kernel.org/stable/c/0f63e33eca6fa29a11c76fa31db5fe1cada5ad6e'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/4a2c5b7994960fac29cf8a3f4e62855bae1b27d4'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/7000ad53ec1b17bd2fac76984b7b0c663755cbb7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00187
epssPercentile: 0.08513
ingestedAt: '2026-08-15T13:26:44.895Z'
---

## Overview

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

f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data

There is issue as follows when test f2fs atomic write:
F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock
F2FS-fs (loop0): invalid crc_offset: 0
F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=1, run fsck to fix.
F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=2, run fsck to fix.
==================================================================
BUG: KASAN: null-ptr-deref in f2fs_get_dnode_of_data+0xac/0x16d0
Read of size 8 at addr 0000000000000028 by task rep/1990

CPU: 4 PID: 1990 Comm: rep Not tainted 5.19.0-rc6-next-20220715 #266
Call Trace:
 <TASK>
 dump_stack_lvl+0x6e/0x91
 print_report.cold+0x49a/0x6bb
 kasan_report+0xa8/0x130
 f2fs_get_dnode_of_data+0xac/0x16d0
 f2fs_do_write_data_page+0x2a5/0x1030
 move_data_page+0x3c5/0xdf0
 do_garbage_collect+0x2015/0x36c0
 f2fs_gc+0x554/0x1d30
 f2fs_balance_fs+0x7f5/0xda0
 f2fs_write_single_data_page+0xb66/0xdc0
 f2fs_write_cache_pages+0x716/0x1420
 f2fs_write_data_pages+0x84f/0x9a0
 do_writepages+0x130/0x3a0
 filemap_fdatawrite_wbc+0x87/0xa0
 file_write_and_wait_range+0x157/0x1c0
 f2fs_do_sync_file+0x206/0x12d0
 f2fs_sync_file+0x99/0xc0
 vfs_fsync_range+0x75/0x140
 f2fs_file_write_iter+0xd7b/0x1850
 vfs_write+0x645/0x780
 ksys_write+0xf1/0x1e0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

As 3db1de0e582c commit changed atomic write way which new a cow_inode for
atomic write file, and also mark cow_inode as FI_ATOMIC_FILE.
When f2fs_do_write_data_page write cow_inode will use cow_inode's cow_inode
which is NULL. Then will trigger null-ptr-deref.
To solve above issue, introduce FI_COW_FILE flag for COW inode.

Fiexes: 3db1de0e582c("f2fs: change the current atomic write way")

## Affected

- `linux_kernel >= 3.8, < 5.18.18`
- `linux_kernel >= 5.19, < 5.19.4`

## Remediation

Upgrade past the affected range:

- `linux_kernel 5.19.4`