Vulnerability in Linux kernel
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-2025-21805 has been found in Linux kernel.
Successful exploitation can lead to full system takeover. CVSS score: 9.8/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-21805" on the vendor's site.
CVE-2025-21805 (Linux kernel) — CVSS v3 9.8
Attack vector: remote (network-reachable) / unauthenticated / no user interaction
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.
A vulnerability (unclassified) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Critical (CVSS 9.8/10). Successful exploitation can lead to full system takeover.
Update to the patched release per vendor advisory.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Audit SBOM/dependencies to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1
Identify exposureidentify
Audit SBOM/dependencies for affected components.資産台帳・SBOM・依存マニフェストで Linux kernel を使っているサービスとバージョンを洗い出す。
-
2
Post-deployment verificationverify
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
| Ecosystem | Package | Affected | Fixed |
|---|---|---|---|
| Linux | Kernel |
≥ 6.12.0, < 6.12.13 ≥ 6.13.0, < 6.13.2 |
6.12.13 6.13.2 |
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2025-21805 linux-lts Fixed in: 6.12.41-r0
- Debian DEBIAN-CVE-2025-21805 linux Fixed in: 6.12.13-1
- Ubuntu UBUNTU-CVE-2025-21805 linux-hwe-edge
Original description The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rtrs: Add missing deinit() call
A warning is triggered when repeatedly connecting and disconnecting the
rnbd:
list_add corruption. prev->next should be next (ffff88800b13e480), but was ffff88801ecd1338. (prev=ffff88801ecd1340).
WARNING: CPU: 1 PID: 36562 at lib/list_debug.c:32 __list_add_valid_or_report+0x7f/0xa0
Workqueue: ib_cm cm_work_handler [ib_cm]
RIP: 0010:__list_add_valid_or_report+0x7f/0xa0
? __list_add_valid_or_report+0x7f/0xa0
ib_register_event_handler+0x65/0x93 [ib_core]
rtrs_srv_ib_dev_init+0x29/0x30 [rtrs_server]
rtrs_ib_dev_find_or_add+0x124/0x1d0 [rtrs_core]
__alloc_path+0x46c/0x680 [rtrs_server]
? rtrs_rdma_connect+0xa6/0x2d0 [rtrs_server]
? rcu_is_watching+0xd/0x40
? __mutex_lock+0x312/0xcf0
? get_or_create_srv+0xad/0x310 [rtrs_server]
? rtrs_rdma_connect+0xa6/0x2d0 [rtrs_server]
rtrs_rdma_connect+0x23c/0x2d0 [rtrs_server]
? __lock_release+0x1b1/0x2d0
cma_cm_event_handler+0x4a/0x1a0 [rdma_cm]
cma_ib_req_handler+0x3a0/0x7e0 [rdma_cm]
cm_process_work+0x28/0x1a0 [ib_cm]
? _raw_spin_unlock_irq+0x2f/0x50
cm_req_handler+0x618/0xa60 [ib_cm]
cm_work_handler+0x71/0x520 [ib_cm]
Commit 667db86bcbe8 ("RDMA/rtrs: Register ib event handler") introduced a
new element .deinit but never used it at all. Fix it by invoking the
deinit() to appropriately unregister the IB event handler.
Source: NIST National Vulnerability Database NVD
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org