Описание
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: cyw: fix heap overflow on a short auth frame
brcmf_notify_auth_frame_rx() takes the frame length from the firmware
event and copies the frame body with the management header offset
subtracted:
u32 mgmt_frame_len = e->datalen - sizeof(struct brcmf_rx_mgmt_data);
...
memcpy(&mgmt_frame->u, frame,
mgmt_frame_len - offsetof(struct ieee80211_mgmt, u));
The only length check is e->datalen >= sizeof(*rxframe), so mgmt_frame_len
can be anything from 0 up. offsetof(struct ieee80211_mgmt, u) is 24. When
mgmt_frame_len is below that, the subtraction wraps as an unsigned value to
a huge length. The memcpy then runs far past the kzalloc'd buffer. A
malicious or malfunctioning AP can make the frame short during the
external SAE auth exchange, so this is a remotely triggered heap overflow.
Reject frames shorter than the management header offset before the copy.
A flaw was found in the Linux kernel's brcmfmac Wi-Fi driver. A remote attacker, by sending a specially crafted short authentication frame during the SAE (Simultaneous Authentication of Equals) authentication exchange, could trigger a heap overflow. This vulnerability allows for potential arbitrary code execution or a denial of service (DoS) on the affected system.
Отчет
This vulnerability is rated as Important severity because an adjacent untrusted access point can trigger memory corruption remotely across the wireless network without prior privileges, risking kernel crashes or code execution. Standard Red Hat Enterprise Linux server deployments do not enable or configure wireless interfaces by default, substantially mitigating practical exposure. The risk is confined to configurations operating compatible Broadcom or Cypress wireless devices connected to networks using Simultaneous Authentication of Equals.
Меры по смягчению последствий
To mitigate this vulnerability, prevent the brcmfmac kernel module from being loaded:
- Create a configuration file to prevent loading the module:
echo "install brcmfmac /bin/true" >> /etc/modprobe.d/disable-brcmfmac.conf
- If the module is currently loaded, unload it:
modprobe -r brcmfmac
If the module is actively in use and cannot be unloaded dynamically, a system reboot is required for the change to take effect. Caveats: Disabling this module will disable wireless network connectivity for any devices that rely on the Broadcom FullMAC (brcmfmac) wireless driver.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Affected | ||
| Red Hat Enterprise Linux 6 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel | Not affected | ||
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel | Not affected | ||
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel-rt | Not affected | ||
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2026:68570 | 17.09.2026 |
| Red Hat Enterprise Linux 9 | kernel | Fixed | RHSA-2026:68570 | 17.09.2026 |
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Дополнительная информация
Статус:
EPSS
8 High
CVSS3
Связанные уязвимости
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: cyw: fix heap overflow on a short auth frame brcmf_notify_auth_frame_rx() takes the frame length from the firmware event and copies the frame body with the management header offset subtracted: u32 mgmt_frame_len = e->datalen - sizeof(struct brcmf_rx_mgmt_data); ... memcpy(&mgmt_frame->u, frame, mgmt_frame_len - offsetof(struct ieee80211_mgmt, u)); The only length check is e->datalen >= sizeof(*rxframe), so mgmt_frame_len can be anything from 0 up. offsetof(struct ieee80211_mgmt, u) is 24. When mgmt_frame_len is below that, the subtraction wraps as an unsigned value to a huge length. The memcpy then runs far past the kzalloc'd buffer. A malicious or malfunctioning AP can make the frame short during the external SAE auth exchange, so this is a remotely triggered heap overflow. Reject frames shorter than the management header offset before the copy.
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: cyw: fix heap overflow on a short auth frame brcmf_notify_auth_frame_rx() takes the frame length from the firmware event and copies the frame body with the management header offset subtracted: u32 mgmt_frame_len = e->datalen - sizeof(struct brcmf_rx_mgmt_data); ... memcpy(&mgmt_frame->u, frame, mgmt_frame_len - offsetof(struct ieee80211_mgmt, u)); The only length check is e->datalen >= sizeof(*rxframe), so mgmt_frame_len can be anything from 0 up. offsetof(struct ieee80211_mgmt, u) is 24. When mgmt_frame_len is below that, the subtraction wraps as an unsigned value to a huge length. The memcpy then runs far past the kzalloc'd buffer. A malicious or malfunctioning AP can make the frame short during the external SAE auth exchange, so this is a remotely triggered heap overflow. Reject frames shorter than the management header offset before the copy.
In the Linux kernel, the following vulnerability has been resolved: w ...
In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: cyw: fix heap overflow on a short auth frame brcmf_notify_auth_frame_rx() takes the frame length from the firmware event and copies the frame body with the management header offset subtracted: u32 mgmt_frame_len = e->datalen - sizeof(struct brcmf_rx_mgmt_data); ... memcpy(&mgmt_frame->u, frame, mgmt_frame_len - offsetof(struct ieee80211_mgmt, u)); The only length check is e->datalen >= sizeof(*rxframe), so mgmt_frame_len can be anything from 0 up. offsetof(struct ieee80211_mgmt, u) is 24. When mgmt_frame_len is below that, the subtraction wraps as an unsigned value to a huge length. The memcpy then runs far past the kzalloc'd buffer. A malicious or malfunctioning AP can make the frame short during the external SAE auth exchange, so this is a remotely triggered heap overflow. Reject frames shorter than the management header offset before the copy.
Important: kernel security, bug fix, and enhancement update
EPSS
8 High
CVSS3