Vulnerability in Linux kernel (CVE-2025-40321)
Summary
Vulnerability in Linux kernel (CVE-2025-40321). 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:
wifi: brcmfmac: fix crash while sending Action Frames in standalone AP Mode
Currently, whenever there is a need to transmit an Action frame,
the brcmfmac driver always uses the P2P vif to send the "actframe" IOVAR to
firmware. The P2P interfaces were available when wpa_supplicant is managing
the wlan interface.
However, the P2P interfaces are not created/initialized when only hostapd
is managing the wlan interface. And if hostapd receives an ANQP Query REQ
Action frame even from an un-associated STA, the brcmfmac driver tries
to use an uninitialized P2P vif pointer for sending the IOVAR to firmware.
This NULL pointer dereferencing triggers a driver crash.
[ 1417.074538] Unable to handle kernel NULL pointer dereference at virtual
address 0000000000000000
[...]
[ 1417.075188] Hardware name: Raspberry Pi 4 Model B Rev 1.5 (DT)
[...]
[ 1417.075653] Call trace:
[ 1417.075662] brcmf_p2p_send_action_frame+0x23c/0xc58 [brcmfmac]
[ 1417.075738] brcmf_cfg80211_mgmt_tx+0x304/0x5c0 [brcmfmac]
[ 1417.075810] cfg80211_mlme_mgmt_tx+0x1b0/0x428 [cfg80211]
[ 1417.076067] nl80211_tx_mgmt+0x238/0x388 [cfg80211]
[ 1417.076281] genl_family_rcv_msg_doit+0xe0/0x158
[ 1417.076302] genl_rcv_msg+0x220/0x2a0
[ 1417.076317] netlink_rcv_skb+0x68/0x140
[ 1417.076330] genl_rcv+0x40/0x60
[ 1417.076343] netlink_unicast+0x330/0x3b8
[ 1417.076357] netlink_sendmsg+0x19c/0x3f8
[ 1417.076370] __sock_sendmsg+0x64/0x…
Source: NIST National Vulnerability Database NVD
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-2025-40321 has been found in Linux kernel.
Risk of unauthorized operations or information disclosure.
What to do: apply the vendor's official patched release.
If unsure, ask your IT team or search "Linux kernel CVE-2025-40321" on the vendor's site.
CVE-2025-40321 (Linux kernel)
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: ?. 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。
Affected packages
Fix status by distribution
Fixed packages published by each distribution for this CVE
- BellSoft Alpaquita BELL-CVE-2025-40321 linux-lts Fixed in: 6.1.159-r0
- Debian DEBIAN-CVE-2025-40321 linux Fixed in: 5.10.247-1
- Ubuntu UBUNTU-CVE-2025-40321 linux
References
- advisory github.com
- advisory nvd.nist.gov
- package git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org
- web git.kernel.org