---
cve: "CVE-2022-50344"
severity: "MEDIUM"
cvss: 5.5
epss: "16%"
vendor: "Linux"
kev: false
exploited: false
published: "2025-09-16 17:15:34"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-18T07:48:21+02:00"
---

# CVE-2022-50344

> 5.5 MEDIUM

## Beschreibung

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

ext4: fix null-ptr-deref in ext4_write_info

I caught a null-ptr-deref bug as follows:
==================================================================
KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f]
CPU: 1 PID: 1589 Comm: umount Not tainted 5.10.0-02219-dirty #339
RIP: 0010:ext4_write_info+0x53/0x1b0
[...]
Call Trace:
 dquot_writeback_dquots+0x341/0x9a0
 ext4_sync_fs+0x19e/0x800
 __sync_filesystem+0x83/0x100
 sync_filesystem+0x89/0xf0
 generic_shutdown_super+0x79/0x3e0
 kill_block_super+0xa1/0x110
 deactivate_locked_super+0xac/0x130
 deactivate_super+0xb6/0xd0
 cleanup_mnt+0x289/0x400
 __cleanup_mnt+0x16/0x20
 task_work_run+0x11c/0x1c0
 exit_to_user_mode_prepare+0x203/0x210
 syscall_exit_to_user_mode+0x5b/0x3a0
 do_syscall_64+0x59/0x70
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
 ==================================================================

Above issue may happen as follows:
-------------------------------------
exit_to_user_mode_prepare
 task_work_run
  __cleanup_mnt
   cleanup_mnt
    deactivate_super
     deactivate_locked_super
      kill_block_super
       generic_shutdown_super
        shrink_dcache_for_umount
         dentry = sb->s_root
         sb->s_root = NULL              s_op->sync_fs > ext4_sync_fs
           dquot_writeback_dquots
            sb->dq_op->write_info > ext4_write_info
             ext4_journal_start(d_inode(sb->s_root), EXT4_HT_QUOTA, 2)
              d_inode(sb->s_root)
               s_root->d_inode

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Gering | warn |
| UI Interaktion | Keine | bad |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Keine | good |
| I Integrität | Keine | good |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 4.9.331
- Kernel ≥ 4.14.296
- Kernel ≥ 4.19.262
- Kernel ≥ 5.4.220
- Kernel ≥ 5.10.150
- Kernel ≥ 5.15.75
- Kernel ≥ 5.19.17
- Kernel ≥ 6.0.3

## Referenzen

- <https://git.kernel.org/stable/c/dc451578446afd03c0c21913993c08898a691435>
- <https://git.kernel.org/stable/c/f4b5ff0b794aa94afac7269c494550ca2f66511b>
- <https://git.kernel.org/stable/c/947264e00c46de19a016fd81218118c708fed2f3>
- <https://git.kernel.org/stable/c/3638aa1c7d87c0ca0aef23cf58cae2c48e7daca4>
- <https://git.kernel.org/stable/c/f34ab95162763cd7352f46df169296eec28b688d>
- <https://git.kernel.org/stable/c/533c60a0b97cee5daab376933f486207e6680fb7>
- <https://git.kernel.org/stable/c/4a657319cfabd6199fd0b7b65bbebf6ded7a11c1>
- <https://git.kernel.org/stable/c/bb420e8afc854d2a1caaa23a0c129839acfb7888>
- <https://git.kernel.org/stable/c/f9c1f248607d5546075d3f731e7607d5571f2b60>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2022-50344) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_