Vulnerability in Kernel (CVE-2025-39731)

Summary

Vulnerability in Kernel (CVE-2025-39731). Risk of unauthorized operations or information disclosure. Mitigation: upgrade to 6.1.148, 6.6.102, 6.12.42, 6.15.10, 6.16.1 or later.

Original description

The description as published by the source.

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

f2fs: vm_unmap_ram() may be called from an invalid context

When testing F2FS with xfstests using UFS backed virtual disks the
kernel complains sometimes that f2fs_release_decomp_mem() calls
vm_unmap_ram() from an invalid context. Example trace from
f2fs/007 test:

f2fs/007 5s ... [12:59:38][ 8.902525] run fstests f2fs/007
[ 11.468026] BUG: sleeping function called from invalid context at mm/vmalloc.c:2978
[ 11.471849] in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 68, name: irq/22-ufshcd
[ 11.475357] preempt_count: 1, expected: 0
[ 11.476970] RCU nest depth: 0, expected: 0
[ 11.478531] CPU: 0 UID: 0 PID: 68 Comm: irq/22-ufshcd Tainted: G W 6.16.0-rc5-xfstests-ufs-g40f92e79b0aa #9 PREEMPT(none)
[ 11.478535] Tainted: [W]=WARN
[ 11.478536] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[ 11.478537] Call Trace:
[ 11.478543]
[ 11.478545] dump_stack_lvl+0x4e/0x70
[ 11.478554] __might_resched.cold+0xaf/0xbe
[ 11.478557] vm_unmap_ram+0x21/0xb0
[ 11.478560] f2fs_release_decomp_mem+0x59/0x80
[ 11.478563] f2fs_free_dic+0x18/0x1a0
[ 11.478565] f2fs_finish_read_bio+0xd7/0x290
[ 11.478570] blk_update_request+0xec/0x3b0
[ 11.478574] ? sbitmap_queue_clear+0x3b/0x60
[ 11.478576] scsi_end_request+0x27/0x1a0
[ 11.478582] scsi_io_completion+0x40/0x300
[ 11.478583] ufshcd_mcq_poll_cqe_lock+0xa3/0xe0
[…

Source: OSV.dev (Open Source Vulnerabilities) NVD OSV

Auto-generated summary

Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.

A vulnerability tracked as CVE-2025-39731 has been found in Kernel.
Risk of unauthorized operations or information disclosure.
What to do: upgrade Kernel to 6.1.148, 6.6.102, 6.12.42, 6.15.10, 6.16.1 or later.
If unsure, ask your IT team or search "Kernel CVE-2025-39731" on the vendor's site.

CVE-2025-39731 (Kernel)
Patched: 6.1.148, 6.6.102, 6.12.42, 6.15.10, 6.16.1 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.

❓ What is the problem

A vulnerability (unclassified) exists in Kernel.

📍 Affected scope

Check the vendor advisory for the affected versions of Kernel.

🔥 Severity

Severity: ?. Risk of unauthorized operations or information disclosure.

🔧 How to fix

Update to 6.1.148, 6.6.102, 6.12.42, 6.15.10, 6.16.1.

🛡️ Workaround

Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.

🔍 Detection

Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'Kernel' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.

Response actions

Concrete steps and command examples for SOC/SRE teams to execute in order

1
Identify exposure identify
```
grep -r 'Kernel' . | grep -v node_modules
```
リポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で Kernel を grep し、稼働しているサービス・バージョンを把握する。
2
Apply patch patch
```
Upgrade Kernel to 6.1.148, 6.6.102, 6.12.42, 6.15.10, 6.16.1
```
ステージング環境で 6.1.148, 6.6.102, 6.12.42, 6.15.10, 6.16.1 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
3
Post-deployment verification verify
```
Confirm patched version is live in production
```
パッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。

Affected packages

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"6.0.0"},{"fixed":"6.1.148"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.102"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.42"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.15.10"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.16.1"}]}]

Fix status by distribution

Fixed packages published by each distribution for this CVE

BellSoft Alpaquita BELL-CVE-2025-39731 linux-lts Fixed in: 6.1.151-r0
Debian DEBIAN-CVE-2025-39731 linux Fixed in: 6.1.148-1
Ubuntu UBUNTU-CVE-2025-39731 linux-hwe-edge