Vulnerability in Linux kernel (CVE-2025-21862)
Summary
Vulnerability in Linux kernel (CVE-2025-21862). Risk of unauthorized operations or information disclosure.
Original description
The description as published by the source.
In the Linux kernel, the following vulnerability has been resolved:
drop_monitor: fix incorrect initialization order
Syzkaller reports the following bug:
BUG: spinlock bad magic on CPU#1, syz-executor.0/7995
lock: 0xffff88805303f3e0, .magic: 00000000, .owner: /-1, .owner_cpu: 0
CPU: 1 PID: 7995 Comm: syz-executor.0 Tainted: G E 5.10.209+ #1
Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x119/0x179 lib/dump_stack.c:118
debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
do_raw_spin_lock+0x1f6/0x270 kernel/locking/spinlock_debug.c:112
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:117 [inline]
_raw_spin_lock_irqsave+0x50/0x70 kernel/locking/spinlock.c:159
reset_per_cpu_data+0xe6/0x240 [drop_monitor]
net_dm_cmd_trace+0x43d/0x17a0 [drop_monitor]
genl_family_rcv_msg_doit+0x22f/0x330 net/netlink/genetlink.c:739
genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
genl_rcv_msg+0x341/0x5a0 net/netlink/genetlink.c:800
netlink_rcv_skb+0x14d/0x440 net/netlink/af_netlink.c:2497
genl_rcv+0x29/0x40 net/netlink/genetlink.c:811
netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
netlink_unicast+0x54b/0x800 net/netlink/af_netlink.c:1348
netlink_sendmsg+0x914/0xe00 net/netlink/af_netlink.c:1916
sock_sendmsg_nosec net/socket.c:651 [inline]
__sock_sendmsg+0x157/0x190 net/socket.c:663
____sys_send…
Source: NIST National Vulnerability Database NVD GitHub Advisory
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-2025-21862 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure. CVSS score: 5.5/10.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-21862" on the vendor's site.
CVE-2025-21862 (Linux kernel) — CWE-908 / CVSS v3 5.5
Attack vector: local / 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 (CWE-908) exists in Linux kernel.
Check the vendor advisory for the affected versions of Linux kernel.
Severity: Medium (CVSS 5.5/10). Risk of unauthorized operations or information disclosure.
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
-
1Identify exposure identify
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。
-
2Post-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。
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2025-21862 linux-lts Fixed in: 6.1.130-r0
- Debian DEBIAN-CVE-2025-21862 linux Fixed in: 5.10.237-1
- Ubuntu UBUNTU-CVE-2025-21862 linux
References
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- patch git.kernel.org
- web lists.debian.org
- web lists.debian.org
- web cert-portal.siemens.com
- web cert-portal.siemens.com
- web nvd.nist.gov
- web github.com
- web cert-portal.siemens.com