Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2 f2fs fs/f2fs/extent_cache.c f2fs_zero_range allocation of resources

CVSS Meta Temp Score
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CTI Interest Score
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4.4$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2 and classified as critical. This affects the function f2fs_zero_range of the file fs/f2fs/extent_cache.c of the component f2fs. Performing a manipulation results in allocation of resources. This vulnerability was named CVE-2025-68796. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical has been found in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2. This affects the function f2fs_zero_range of the file fs/f2fs/extent_cache.c of the component f2fs. The manipulation with an unknown input leads to a allocation of resources vulnerability. CWE is classifying the issue as 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: f2fs: fix to avoid updating zero-sized extent in extent cache As syzbot reported: F2FS-fs (loop0): __update_extent_tree_range: extent len is zero, type: 0, extent [0, 0, 0], age [0, 0] ------------[ cut here ]------------ kernel BUG at fs/f2fs/extent_cache.c:678! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 5336 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__update_extent_tree_range+0x13bc/0x1500 fs/f2fs/extent_cache.c:678 Call Trace: <TASK> f2fs_update_read_extent_cache_range+0x192/0x3e0 fs/f2fs/extent_cache.c:1085 f2fs_do_zero_range fs/f2fs/file.c:1657 [inline] f2fs_zero_range+0x10c1/0x1580 fs/f2fs/file.c:1737 f2fs_fallocate+0x583/0x990 fs/f2fs/file.c:2030 vfs_fallocate+0x669/0x7e0 fs/open.c:342 ioctl_preallocate fs/ioctl.c:289 [inline] file_ioctl+0x611/0x780 fs/ioctl.c:-1 do_vfs_ioctl+0xb33/0x1430 fs/ioctl.c:576 __do_sys_ioctl fs/ioctl.c:595 [inline] __se_sys_ioctl+0x82/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f07bc58eec9 In error path of f2fs_zero_range(), it may add a zero-sized extent into extent cache, it should be avoided.

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2025-68796 since 12/24/2025. The exploitability is told 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 298659 (Debian dla-4476 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.160, 6.6.120, 6.12.64, 6.18.3 or 6.19-rc1 eliminates this vulnerability. Applying the patch e50b81c50fcbe63f50405bb40f262162ff32af88/efe3371001f50a2d6f746b50bdc6f9f26b2089ec/4f244c64efe628d277b916f47071adf480eb8646/bac23833220a1f8fe8dfab7e16efa20ff64d7589/7c37c79510329cd951a4dedf3f7bf7e2b18dccec 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 (298659) and CERT Bund (WID-SEC-2026-0086). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • RESF Rocky Linux
  • Open Source Linux Kernel

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.6
VulDB Meta Temp Score: 4.4

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

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Allocation of resources
CWE: CWE-770 / CWE-400 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298659
Nessus Name: Debian dla-4476 : linux-config-6.1 - security update

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.160/6.6.120/6.12.64/6.18.3/6.19-rc1
Patch: e50b81c50fcbe63f50405bb40f262162ff32af88/efe3371001f50a2d6f746b50bdc6f9f26b2089ec/4f244c64efe628d277b916f47071adf480eb8646/bac23833220a1f8fe8dfab7e16efa20ff64d7589/7c37c79510329cd951a4dedf3f7bf7e2b18dccec

Timelineinfo

12/24/2025 CVE reserved
01/13/2026 +20 days Advisory disclosed
01/13/2026 +0 days VulDB entry created
03/27/2026 +73 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-68796 (🔒)
GCVE (CVE): GCVE-0-2025-68796
GCVE (VulDB): GCVE-100-340623
CERT Bund: WID-SEC-2026-0086 - Linux Kernel: Mehrere Schwachstellen

Entryinfo

Created: 01/13/2026 17:26
Updated: 03/27/2026 08:01
Changes: 01/13/2026 17:26 (60), 01/16/2026 02:21 (1), 02/12/2026 04:50 (2), 03/27/2026 08:01 (7)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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