Live › vulnerability › CVE-2026-99061
Go to dashboardWhen the brcmfmac Wi-Fi driver is removed while wpa_supplicant is still exiting, the P2P device interface is removed twice and the kernel oopses. The sources describe a crash (denial of service) and do not describe code execution.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Systems that load the brcmfmac Wi-Fi driver (Broadcom/Cypress/Infineon chips on SDIO, such as the CYW55513 on an i.MX 8M Plus board) and where wpa_supplicant creates a P2P device. The crash needs the driver to be removed or unloaded while wpa_supplicant is still exiting, so systems that never unload brcmfmac are unlikely to hit it. unknown whether other bus types are affected.
No product ranges from the sources yet.
uname -r and check whether the kernel includes the brcmfmac fix for the P2P device removal race in brcmf_detach()lsmod | grep brcmfmac to see whether the brcmfmac driver is loaded on the machineiw dev to see whether a P2P-device interface exists on a Broadcom/Cypress SDIO Wi-Fi boardEach row is the first time that source carried this signal. The analyst’s rows are its own findings.
In the Linux kernel, the following vulnerability has been resolved:
wifi: brcmfmac: fix P2P device removal race in brcmf_detach()
When the driver is removed while the user space process that created the P2P device (e.g. wpa_supplicant) is still exiting, the P2P device interface is removed twice and the kernel crashes.
The two paths are:
wpa_supplicant, on exit, sends NL80211_CMD_DEL_INTERFACE for the P2P device. nl80211_del_interface() holds RTNL and the wiphy mutex and calls brcmf_p2p_del_vif(), which disables discovery and waits up to 1.5 s for BRCMF_E_IF_DEL. Then it calls brcmf_remove_interface(), which unregisters the wdev and frees the vif and the ifp.
brcmf_detach() sets the bus down, so BRCMF_E_IF_DEL never arrives, and calls brcmf_remove_interface(ifp, false) for the same ifp. brcmf_p2p_ifp_removed() reads ifp->vif and then blocks on rtnl_lock(). When brcmf_p2p_del_vif() releases RTNL, it calls cfg80211_unregister_wdev() on the wdev that was already unregistered and freed.
The second list_del_rcu() of wdev->list faults on LIST_POISON2:
brcmfmac: brcmf_p2p_del_vif delete P2P vif brcmfmac: brcmf_p2p_deinit_discovery enter brcmfmac: brcmf_p2p_del_vif P2P: GO_NEG_PHASE status cleared brcmfmac: brcmf_detach Enter brcmfmac: brcmf_bus_change_state 1 -> 0 brcmfmac: brcmf_remove_interface Enter, bsscfgidx=1, ifidx=0 brcmfmac: brcmf_del_if Enter, bsscfgidx=1, ifidx=0 brcmfmac: brcmf_p2p_ifp_removed P2P: device interface removed [1.5 s later, brcmf_p2p_del_vif() timed out] brcmfmac: brcmf_remove_interface Enter, bsscfgidx=1, ifidx=0 brcmfmac: brcmf_del_if Enter, bsscfgidx=1, ifidx=0 brcmfmac: brcmf_p2p_ifp_removed P2P: device interface removed Unable to handle kernel paging request at virtual address dead000000000122 Internal error: Oops: 96000044 [#1] PREEMPT_RT SMP pc : _cfg80211_unregister_wdev+0x6c/0x264 [cfg80211] Call trace: _cfg80211_unregister_wdev+0x6c/0x264 [cfg80211] cfg80211_unregister_wdev+0x10/0x1c [cfg80211] brcmf_p2p_ifp_removed+0x84/0xb0 [brcmfmac] brcmf_remove_interface+0x1f4/0x254 [brcmfmac] brcmf_detach+0x88/0x180 [brcmfmac] brcmf_sdio_remove+0x90/0x7b0 [brcmfmac] brcmf_sdiod_remove+0x20/0xa0 [brcmfmac] brcmf_ops_sdio_remove+0xbc/0x12c [brcmfmac] sdio_bus_remove+0x38/0x144 device_release_driver_internal+0x1e8/0x2c0 device_release_driver+0x14/0x20 brcmf_sdio_bus_remove+0x2c/0x40 [brcmfmac] brcmf_fwvid_unregister_vendor+0xd8/0x170 [brcmfmac] __exit_compat+0x18/0x418 [brcmfmac_cyw] __arm64_sys_delete_module+0x1ac/0x244
The log was taken with debug=0x406 on an i.MX 8M Plus board with a CYW55513 (Sona IF513) on SDIO. The driver is the Ezurio backport of brcmfmac from v6.18.22 on a 5.4-rt kernel. The code involved is the same in mainline.
To reproduce:
Start wpa_supplicant on wlan0 and let it associate. It creates the P2P device (iw dev shows "type P2P-device").
Stop wpa_supplicant and remove the driver without waiting for wpa_supplicant to exit:
kill $(pidof wpa_supplicant) rmmod brcmfmac_cyw brcmfmac
The crash is reproducible on that board.
For the interface without a netdev (the P2P device), take RTNL and the wiphy mutex in brcmf_detach() before reading iflist, and remove it with locked=true. If brcmf_p2p_del_vif() runs first, brcmf_detach() finds the slot empty. If brcmf_detach() runs first, nl80211 does not find the wdev any more. The interfaces with a netdev are removed as before, because brcmf_del_if() takes RTNL on its own for the primary interface.
This page as .md · .json · in your agent: get_signal("CVE-2026-99061")
NVD data is provided by NIST and is public domain · EPSS scores by FIRST, used with attribution. Posts quoted belong to their authors.