Linux Kernel up to 5.15.162/6.1.97/6.6.38/6.9.8 btrfs_delete_unused_bgs allocation of resources

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
4.9	$0-$5k	0.00

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 5.15.162/6.1.97/6.6.38/6.9.8. The affected element is the function btrfs_delete_unused_bgs. This manipulation causes allocation of resources. This vulnerability is handled as CVE-2024-42103. There is not any exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.15.162/6.1.97/6.6.38/6.9.8. Affected by this vulnerability is the function btrfs_delete_unused_bgs. The manipulation with an unknown input leads to a allocation of resources vulnerability. The CWE definition for the vulnerability is CWE-770. The product allocates a reusable resource or group of resources on behalf of an actor without imposing any restrictions on the size or number of resources that can be allocated, in violation of the intended security policy for that actor. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix adding block group to a reclaim list and the unused list during reclaim There is a potential parallel list adding for retrying in btrfs_reclaim_bgs_work and adding to the unused list. Since the block group is removed from the reclaim list and it is on a relocation work, it can be added into the unused list in parallel. When that happens, adding it to the reclaim list will corrupt the list head and trigger list corruption like below. Fix it by taking fs_info->unused_bgs_lock. [177.504][T2585409] BTRFS error (device nullb1): error relocating ch= unk 2415919104 [177.514][T2585409] list_del corruption. next->prev should be ff1100= 0344b119c0, but was ff11000377e87c70. (next=3Dff110002390cd9c0) [177.529][T2585409] ------------[ cut here ]------------ [177.537][T2585409] kernel BUG at lib/list_debug.c:65! [177.545][T2585409] Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN NOPTI [177.555][T2585409] CPU: 9 PID: 2585409 Comm: kworker/u128:2 Tainted: G W 6.10.0-rc5-kts #1 [177.568][T2585409] Hardware name: Supermicro SYS-520P-WTR/X12SPW-TF, BIOS 1.2 02/14/2022 [177.579][T2585409] Workqueue: events_unbound btrfs_reclaim_bgs_work[btrfs] [177.589][T2585409] RIP: 0010:__list_del_entry_valid_or_report.cold+0x70/0x72 [177.624][T2585409] RSP: 0018:ff11000377e87a70 EFLAGS: 00010286 [177.633][T2585409] RAX: 000000000000006d RBX: ff11000344b119c0 RCX:0000000000000000 [177.644][T2585409] RDX: 000000000000006d RSI: 0000000000000008 RDI:ffe21c006efd0f40 [177.655][T2585409] RBP: ff110002e0509f78 R08: 0000000000000001 R09:ffe21c006efd0f08 [177.665][T2585409] R10: ff11000377e87847 R11: 0000000000000000 R12:ff110002390cd9c0 [177.676][T2585409] R13: ff11000344b119c0 R14: ff110002e0508000 R15:dffffc0000000000 [177.687][T2585409] FS: 0000000000000000(0000) GS:ff11000fec880000(0000) knlGS:0000000000000000 [177.700][T2585409] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [177.709][T2585409] CR2: 00007f06bc7b1978 CR3: 0000001021e86005 CR4:0000000000771ef0 [177.720][T2585409] DR0: 0000000000000000 DR1: 0000000000000000 DR2:0000000000000000 [177.731][T2585409] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:0000000000000400 [177.742][T2585409] PKRU: 55555554 [177.748][T2585409] Call Trace: [177.753][T2585409] [177.759][T2585409] ? __die_body.cold+0x19/0x27 [177.766][T2585409] ? die+0x2e/0x50 [177.772][T2585409] ? do_trap+0x1ea/0x2d0 [177.779][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72 [177.788][T2585409] ? do_error_trap+0xa3/0x160 [177.795][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72 [177.805][T2585409] ? handle_invalid_op+0x2c/0x40 [177.812][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72 [177.820][T2585409] ? exc_invalid_op+0x2d/0x40 [177.827][T2585409] ? asm_exc_invalid_op+0x1a/0x20 [177.834][T2585409] ? __list_del_entry_valid_or_report.cold+0x70/0x72 [177.843][T2585409] btrfs_delete_unused_bgs+0x3d9/0x14c0 [btrfs] There is a similar retry_list code in btrfs_delete_unused_bgs(), but it is safe, AFAICS. Since the block group was in the unused list, the used bytes should be 0 when it was added to the unused list. Then, it checks block_group->{used,reserved,pinned} are still 0 under the block_group->lock. So, they should be still eligible for the unused list, not the reclaim list. The reason it is safe there it's because because we're holding space_info->groups_sem in write mode. That means no other task can allocate from the block group, so while we are at deleted_unused_bgs() it's not possible for other tasks to allocate and deallocate extents from the block group, so it can't be added to the unused list or the reclaim list by anyone else. The bug can be reproduced by btrfs/166 after a few rounds. In practice this can be hit when relocation cannot find more chunk space and ends with ENOSPC.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2024-42103 since 07/29/2024. The exploitation appears to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 210060 (Ubuntu 22.04 LTS / 24.04 LTS : Linux kernel kernel vulnerabilities (USN-7089-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.163, 6.1.98, 6.6.39 or 6.9.9 eliminates this vulnerability. Applying the patch 522b39bd7163/aa1d8cc0cc50/f8e960be923f/326fa14549d7/48f091fd50b2 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 databases at Tenable (210060) and CERT Bund (WID-SEC-2024-1722). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• IBM InfoSphere Guardium
• Oracle Linux
• NetApp FAS
• NetApp ActiveIQ Unified Manager
• Siemens SIMATIC S7
• Oracle VM
• IBM Security Guardium
• RESF Rocky Linux
• Broadcom Brocade SANnav
• Dell PowerScale
• Open Source Linux Kernel
• IBM QRadar SIEM
• Dell integrated Dell Remote Access Controller
• IBM Storage Scale
• IBM Spectrum Protect Plus
• Juniper Junos Space
• IBM Storage Scale System
• SolarWinds Security Event Manager

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.15.162
• 6.1.0
• 6.1.1
• 6.1.2
• 6.1.3
• 6.1.4
• 6.1.5
• 6.1.6
• 6.1.7
• 6.1.8
• 6.1.9
• 6.1.10
• 6.1.11
• 6.1.12
• 6.1.13
• 6.1.14
• 6.1.15
• 6.1.16
• 6.1.17
• 6.1.18
• 6.1.19
• 6.1.20
• 6.1.21
• 6.1.22
• 6.1.23
• 6.1.24
• 6.1.25
• 6.1.26
• 6.1.27
• 6.1.28
• 6.1.29
• 6.1.30
• 6.1.31
• 6.1.32
• 6.1.33
• 6.1.34
• 6.1.35
• 6.1.36
• 6.1.37
• 6.1.38
• 6.1.39
• 6.1.40
• 6.1.41
• 6.1.42
• 6.1.43
• 6.1.44
• 6.1.45
• 6.1.46
• 6.1.47
• 6.1.48
• 6.1.49
• 6.1.50
• 6.1.51
• 6.1.52
• 6.1.53
• 6.1.54
• 6.1.55
• 6.1.56
• 6.1.57
• 6.1.58
• 6.1.59
• 6.1.60
• 6.1.61
• 6.1.62
• 6.1.63
• 6.1.64
• 6.1.65
• 6.1.66
• 6.1.67
• 6.1.68
• 6.1.69
• 6.1.70
• 6.1.71
• 6.1.72
• 6.1.73
• 6.1.74
• 6.1.75
• 6.1.76
• 6.1.77
• 6.1.78
• 6.1.79
• 6.1.80
• 6.1.81
• 6.1.82
• 6.1.83
• 6.1.84
• 6.1.85
• 6.1.86
• 6.1.87
• 6.1.88
• 6.1.89
• 6.1.90
• 6.1.91
• 6.1.92
• 6.1.93
• 6.1.94
• 6.1.95
• 6.1.96
• 6.1.97
• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.9.0
• 6.9.1
• 6.9.2
• 6.9.3
• 6.9.4
• 6.9.5
• 6.9.6
• 6.9.7
• 6.9.8

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: 5.0
VulDB Meta Temp Score: 4.9

VulDB Base Score: 4.6
VulDB Temp Score: 4.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 5.5
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: Allocation of resources
CWE: CWE-770 / CWE-400 / 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: 210060
Nessus Name: Ubuntu 22.04 LTS / 24.04 LTS : Linux kernel kernel vulnerabilities (USN-7089-1)

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔍

Upgrade: Kernel 5.15.163/6.1.98/6.6.39/6.9.9
Patch: 522b39bd7163/aa1d8cc0cc50/f8e960be923f/326fa14549d7/48f091fd50b2

Timelineinfo

07/29/2024 🔍
07/30/2024 +1 days 🔍
07/30/2024 +0 days 🔍
09/26/2025 +423 days 🔍

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2024-42103 (🔍)
GCVE (CVE): GCVE-0-2024-42103
GCVE (VulDB): GCVE-100-272971
CERT Bund: WID-SEC-2024-1722 - Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff

Entryinfo

Created: 07/30/2024 10:15
Updated: 09/26/2025 18:24
Changes: 07/30/2024 10:15 (57), 11/02/2024 04:08 (3), 07/15/2025 22:10 (7), 07/19/2025 19:31 (1), 09/26/2025 18:24 (12)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

Do you want to use VulDB in your project?

Use the official API to access entries easily!