Description
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:
1. Start wpa_supplicant on wlan0 and let it associate. It creates the
P2P device (iw dev shows "type P2P-device").
2. 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.
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:
1. Start wpa_supplicant on wlan0 and let it associate. It creates the
P2P device (iw dev shows "type P2P-device").
2. 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.
Published:
2026-10-23
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
Analysis
Analysis and contextual insights are available on OpenCVE Cloud.
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
||||||||||||||||||||||||
| Linux | Linux | affected |
|
No data.
No data.
No data available yet.
Remediation
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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Advisories
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References
History
Fri, 23 Oct 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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: 1. Start wpa_supplicant on wlan0 and let it associate. It creates the P2P device (iw dev shows "type P2P-device"). 2. 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. | |
| Title | wifi: brcmfmac: fix P2P device removal race in brcmf_detach() | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-23T12:22:59.770Z
Reserved: 2026-09-25T10:25:14.388Z
Link: CVE-2026-99061
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.