PT-2025-18567 · Linux+2 · Linux Kernel+2

Published 2025-05-01 · Updated 2025-07-10 · CVE-2022-49850

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

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

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description A semaphore deadlock can occur in the Linux kernel if nilfs get block() detects metadata corruption while locating data blocks and a superblock writeback occurs at the same time. This happens due to the hierarchical lock acquisition in the order rwsem A -> rwsem B. The deadlock occurs when another task starts updating the superblock, causing it to writelock rwsem B and then try to readlock rwsem A in nilfs count free blocks(). However, there is no need to take rwsem A in nilfs count free blocks() because it only reads a single integer data on a shared struct with nilfs sufile get ncleansegs().

Recommendations As a temporary workaround, consider disabling the nilfs count free blocks() function until a patch is available. To resolve the issue, the nilfs count free blocks() function has been modified to not take the semaphore, thus preventing the deadlock.

Exploit

Fix

Improper Locking

Weakness Enumeration

CWE-667

Related Identifiers

CVE-2022-49850

OESA-2025-1513

SUSE-SU-2025:01918-1

SUSE-SU-2025:01966-1

SUSE-SU-2025:02173-1

SUSE-SU-2025:02262-1

SUSE-SU-2025:2173-1

SUSE-SU-2025_02173-1

SUSE-SU-2025_02262-1

Affected Products

Astra Linux

Linux Kernel

Suse

References · 461

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49850.json · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2022-49771 · Security Note
• https://git.kernel.org/stable/c/abc082aac0d9b6b926038fc3adb7008306581be2 · Patch
• https://security-tracker.debian.org/tracker/CVE-2022-49850 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2022-49826 · Security Note
• https://cve.org/CVERecord?id=CVE-2022-49850 · Security Note
• https://git.kernel.org/stable/c/f0cc93080d4c09510b74ecba87fd778cca390bb1 · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2022-49915 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2022-49842 · Security Note
• https://git.kernel.org/stable/c/cb029b54953420f7a2d65100f1c5107f14411bdc · Patch
• https://ubuntu.com/security/CVE-2022-49850 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2022-49850 · Vendor Advisory
• https://osv.dev/vulnerability/SUSE-SU-2025:02262-1 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2022-49111 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2023-53090 · Security Note