---
cve: "CVE-2022-48674"
severity: "HIGH"
cvss: 7.8
epss: "0.2%"
vendor: "Linux"
kev: false
exploited: false
published: "2024-05-03 15:15:07"
tags: [cve, security, high]
source: tsecurity.de CVE-Dossier
exported: "2026-09-20T16:06:40+02:00"
---

# CVE-2022-48674

> 7.8 HIGH

## Beschreibung

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

erofs: fix pcluster use-after-free on UP platforms

During stress testing with CONFIG_SMP disabled, KASAN reports as below:

==================================================================
BUG: KASAN: use-after-free in __mutex_lock+0xe5/0xc30
Read of size 8 at addr ffff8881094223f8 by task stress/7789

CPU: 0 PID: 7789 Comm: stress Not tainted 6.0.0-rc1-00002-g0d53d2e882f9 #3
Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011
Call Trace:
 
..
 __mutex_lock+0xe5/0xc30
..
 z_erofs_do_read_page+0x8ce/0x1560
..
 z_erofs_readahead+0x31c/0x580
..
Freed by task 7787
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x20/0x30
 kasan_set_free_info+0x20/0x40
 __kasan_slab_free+0x10c/0x190
 kmem_cache_free+0xed/0x380
 rcu_core+0x3d5/0xc90
 __do_softirq+0x12d/0x389

Last potentially related work creation:
 kasan_save_stack+0x1e/0x40
 __kasan_record_aux_stack+0x97/0xb0
 call_rcu+0x3d/0x3f0
 erofs_shrink_workstation+0x11f/0x210
 erofs_shrink_scan+0xdc/0x170
 shrink_slab.constprop.0+0x296/0x530
 drop_slab+0x1c/0x70
 drop_caches_sysctl_handler+0x70/0x80
 proc_sys_call_handler+0x20a/0x2f0
 vfs_write+0x555/0x6c0
 ksys_write+0xbe/0x160
 do_syscall_64+0x3b/0x90

The root cause is that erofs_workgroup_unfreeze() doesn't reset to
orig_val thus it causes a race that the pcluster reuses unexpectedly
before freeing.

Since UP platforms are quite rare now, such path becomes unnecessary.
Let's drop such specific-designed path directly instead.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 | Hoch | bad |
| I Integrität | Hoch | bad |
| A Verfügbarkeit | Hoch | bad |

## Patch verfügbar (OSV)

- Kernel ≥ 5.15.68
- Kernel ≥ 5.19.9

## Referenzen

- <https://git.kernel.org/stable/c/8ddd001cef5e82d19192e6861068463ecca5f556>
- <https://git.kernel.org/stable/c/94c34faaafe7b55adc2d8d881db195b646959b9e>
- <https://git.kernel.org/stable/c/2f44013e39984c127c6efedf70e6b5f4e9dcf315>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2022-48674) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_