Linux Kernel up to 5.18.1 lock_zspage null pointer dereference

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4.6	$0-$5k	0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 5.18.1. It has been rated as critical. This vulnerability affects the function lock_zspage. This manipulation causes null pointer dereference. This vulnerability is tracked as CVE-2022-49554. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability has been found in Linux Kernel up to 5.18.1 and classified as critical. Affected by this vulnerability is the function lock_zspage. The manipulation with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: zsmalloc: fix races between asynchronous zspage free and page migration The asynchronous zspage free worker tries to lock a zspage's entire page list without defending against page migration. Since pages which haven't yet been locked can concurrently migrate off the zspage page list while lock_zspage() churns away, lock_zspage() can suffer from a few different lethal races. It can lock a page which no longer belongs to the zspage and unsafely dereference page_private(), it can unsafely dereference a torn pointer to the next page (since there's a data race), and it can observe a spurious NULL pointer to the next page and thus not lock all of the zspage's pages (since a single page migration will reconstruct the entire page list, and create_page_chain() unconditionally zeroes out each list pointer in the process). Fix the races by using migrate_read_lock() in lock_zspage() to synchronize with page migration.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2022-49554 since 02/26/2025. The exploitation appears to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 238226 (EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-1635)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 4.14.282, 4.19.246, 5.4.197, 5.10.120, 5.15.45, 5.17.13 or 5.18.2 eliminates this vulnerability. Applying the patch 3674d8a8dadd03a447dd21069d4dacfc3399b63b/645996efc2ae391246d595832aaa6f9d3cc338c7/fc658c083904427abbf8f18280d517ee2668677c/fae05b2314b147a78fbed1dc4c645d9a66313758/3ec459c8810e658401be428d3168eacfc380bdd0/8ba7b7c1dad1f6503c541778f31b33f7f62eb966/c5402fb5f71f1a725f1e55d9c6799c0c7bec308f/2505a981114dcb715f8977b8433f7540854851d8 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (238226). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 4.14.281
• 4.19.245
• 5.4.196
• 5.10.119
• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.15.33
• 5.15.34
• 5.15.35
• 5.15.36
• 5.15.37
• 5.15.38
• 5.15.39
• 5.15.40
• 5.15.41
• 5.15.42
• 5.15.43
• 5.15.44
• 5.17.0
• 5.17.1
• 5.17.2
• 5.17.3
• 5.17.4
• 5.17.5
• 5.17.6
• 5.17.7
• 5.17.8
• 5.17.9
• 5.17.10
• 5.17.11
• 5.17.12
• 5.18.0
• 5.18.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔍
• 🔍
• 🔍

CPE 2.2info

• 🔍
• 🔍
• 🔍

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.6

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 4.7
NVD Vector: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: Partially

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Nessus ID: 238226
Nessus Name: EulerOS 2.0 SP13 : kernel (EulerOS-SA-2025-1635)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 4.14.282/4.19.246/5.4.197/5.10.120/5.15.45/5.17.13/5.18.2
Patch: 3674d8a8dadd03a447dd21069d4dacfc3399b63b/645996efc2ae391246d595832aaa6f9d3cc338c7/fc658c083904427abbf8f18280d517ee2668677c/fae05b2314b147a78fbed1dc4c645d9a66313758/3ec459c8810e658401be428d3168eacfc380bdd0/8ba7b7c1dad1f6503c541778f31b33f7f62eb966/c5402fb5f71f1a725f1e55d9c6799c0c7bec308f/2505a981114dcb715f8977b8433f7540854851d8

Timelineinfo

02/26/2025 🔍
02/26/2025 +0 days 🔍
02/26/2025 +0 days 🔍
10/23/2025 +239 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2022-49554 (🔍)
GCVE (CVE): GCVE-0-2022-49554
GCVE (VulDB): GCVE-100-297157

Entryinfo

Created: 02/26/2025 10:37
Updated: 10/23/2025 02:08
Changes: 02/26/2025 10:37 (58), 06/12/2025 19:49 (2), 10/23/2025 02:08 (10)
Complete: 🔍
Cache ID: 216::103

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