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Fencer Vulns
no cvss —

CVE-2025-40321 json

wifi: brcmfmac: fix crash while sending Action Frames in standalone AP Mode

published 2025-12-08 11 mo ago modified 2026-10-14 25 d ago also EUVD-2025-201624

cvss
—
not scored
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 12%
public exploits
0
none known

Summary

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+0x64/0xc0 [ 1417.076391] ____sys_sendmsg+0x268/0x2a0 [ 1417.076408] ___sys_sendmsg+0xb8/0x118 [ 1417.076427] __sys_sendmsg+0x90/0xf8 [ 1417.076445] __arm64_sys_sendmsg+0x2c/0x40 [ 1417.076465] invoke_syscall+0x50/0x120 [ 1417.076486] el0_svc_common.constprop.0+0x48/0xf0 [ 1417.076506] do_el0_svc+0x24/0x38 [ 1417.076525] el0_svc+0x30/0x100 [ 1417.076548] el0t_64_sync_handler+0x100/0x130 [ 1417.076569] el0t_64_sync+0x190/0x198 [ 1417.076589] Code: f9401e80 aa1603e2 f9403be1 5280e483 (f9400000)

Fix this, by always using the vif corresponding to the wdev on which the Action frame Transmission request was initiated by the userspace. This way, even if P2P vif is not available, the IOVAR is sent to firmware on AP vif and the ANQP Query RESP Action frame is transmitted without crashing the driver.

Move init_completion() for "send_af_done" from brcmf_p2p_create_p2pdev() to brcmf_p2p_attach(). Because the former function would not get executed when only hostapd is managing wlan interface, and it is not safe to do reinit_completion() later in brcmf_p2p_tx_action_frame(), without any prior init_completion().

And in the brcmf_p2p_tx_action_frame() function, the condition check for P2P Presence response frame is not needed, since the wpa_supplicant is properly sending the P2P Presense Response frame on the P2P-GO vif instead of the P2P-Device vif.

[Cc stable]

Patch / fix

  • Linux Linux 5.4.302, 5.10.247, 5.15.197, 6.1.159, 6.6.117, 6.12.58, 6.17.8, 6.18
  • linux Debian 12 6.1.159-1
  • linux Debian 13 6.12.63-1
  • linux Debian 14 6.17.8-1

debian advisories DEBIAN-CVE-2025-40321

  • linux Ubuntu 22.04 LTS 5.15.0-173.183
  • linux Ubuntu 24.04 LTS 6.8.0-106.106
  • linux Ubuntu 25.10 6.17.0-14.14
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1103.110
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1050.53
  • linux-aws Ubuntu 25.10 6.17.0-1007.7
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1103.112
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1052.55

ubuntu advisories UBUNTU-CVE-2025-40321

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-40.1
  • kernel-source Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-kvmsmall Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1
  • kernel-default-base Linux Micro 6.1, Linux Micro 6.0 6.4.0-39.1.21.16
  • kernel-rt Linux Micro 6.2 6.12.0-160000.9.1
  • kernel-64kb SLES 16.0, Linux Micro 6.2, SLES for SAP applications 16.0 6.12.0-160000.9.1

suse advisories SUSE-SU-2026:20845-1SUSE-SU-2026:20876-1SUSE-SU-2026:20477-1SUSE-SU-2026:20498-1SUSE-SU-2026:20207-1SUSE-SU-2026:20220-1

  • kernel-rt openSUSE Leap 16.0 6.12.0-160000.9.1
  • dtb-aarch64 openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-64kb openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-syms openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-azure openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-obs-qa openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-source openSUSE Leap 16.0 6.12.0-160000.9.1
  • kernel-default openSUSE Leap 16.0 6.12.0-160000.9.1

opensuse advisories openSUSE-SU-2026:20145-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-40321 updated cvss 6.4

kernel: wifi: brcmfmac: fix crash while sending Action Frames in standalone AP Mode

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    affected: workaround, no fix available
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.22% chance of exploitation in the next 30 days, higher than 12% of all scored CVEs (FIRST EPSS, 2026-11-08).

Affected products

  • Linux Linux

Classification

Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.