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CVE-2026-98330
wifi: cfg80211: get the wiphy out of a dying network namespace
Published 2026-10-06 (13 days ago) by the Linux kernel CNA. Subsystem net/wireless. Debian urgency: not yet assigned.
What to do, per Debian release
Debian's own status for CVE-2026-98330 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | vulnerable | 6.1.190-1 | No fix published anywhere yet, neither in Debian nor upstream for the series bookworm tracks. Watch the Debian tracker page for this CVE. Advisories for bookworm have historically landed a median of 23 days after publication. |
| Debian 13trixie | vulnerable | 6.12.113-1 | No fix published anywhere yet, neither in Debian nor upstream for the series trixie tracks. Watch the Debian tracker page for this CVE. Advisories for trixie have historically landed a median of 11 days after publication. |
| Debian 14forky | fixed | 7.2.8-1 | Update the kernel and reboot. Fixed in 7.2.8-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.2.8-1 | Update the kernel and reboot. Fixed in 7.2.8-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
When a network namespace is destroyed, cfg80211_pernet_exit() moves any wiphy back to the initial namespace, and just warns if that fails. But moving an interface can fail (due to allocation failures), and then the wiphy is left behind with a garbage netns pointer: Kernel mode fault at addr 0x30 genlmsg_multicast_netns.constprop.0+0x46/0xcf [cfg80211] nl80211_notify_wiphy+0xcd/0xe8 [cfg80211] wiphy_unregister+0x169/0x3fc [cfg80211] Note that commit debac3a20dec ("net: Remove conflicting altnames for dying netns in __dev_change_net_namespace().") fixed another path that could reach it without allocation failures. Remove interfaces that cannot be moved instead of failing the switch, so that the wiphy always ends up in the initial namespace. In this case the netdev core will unregister the interfaces anyway.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
net/wireless/core.c
- What this is
- 802.11 (including CFG80211/NL80211)MAINTAINERS section matched on net/wireless/ · linux-wireless@vger.kernel.org · Maintained
- Kernel module
- cfg80211
Check it on the machine
grep -wE 'CONFIG_CFG80211|CONFIG_WIRELESS' /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w cfg80211Prints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed.
- bookwormMnot built on amd64/cloud-amd64, arm64/cloud-arm64
- trixie, forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- M
- a module where it is built at all; some flavours do not build it
- Build switches
- CONFIG_CFG80211, CONFIG_WIRELESS
- Reads as
- all on means the file is compiled; any one off means it is not.
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-10-06 (13 days ago)source
- CVSS
- 7.0 high
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.13%, higher than 2.2% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- not yet assignedsource
- Subsystem
- net/wireless
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 2.6.32 | 6.18.54 | caa02072b298 |
| 2.6.32 | 7.2.8 | b949b2720688 |
| 2.6.32 | 7.3 | 4635b1a1c1d6 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- Everything is local netlink: NL80211_CMD_SET_WIPHY_NETNS moves the wiphy into a namespace, RTM_NEWLINKPROP adds an altname, and the namespace is then torn down. cfg80211_pernet_exit() calls __cfg80211_switch_netns(); dev_change_net_namespace() fails and the wiphy keeps a pointer to the freed netns. No WiFi frame is involved.
- AC:HAttack complexity, high
- A wiphy only reaches a non-init netns if real root delegates it, since hwsim radios made in a userns are deleted by hwsim_exit_net() first. The forced failure (an altname clashing with an init_net device) works only on kernels without debac3a20dec; on others the switch fails only on allocation failure. The attacker cannot cause either precondition.
- PR:LPrivileges required, low
- Once a wiphy has been delegated to a container, container root needs only CAP_NET_ADMIN in its own user namespace. That passes GENL_UNS_ADMIN_PERM and the ns_capable() check on the target in nl80211_wiphy_netns() for a nested netns, and lets it add the clashing altname with RTM_NEWLINKPROP. No init-namespace privilege is required.
- UI:NUser interaction, none
- The attacker moves the wiphy, adds the altname and destroys the nested netns on their own, so no victim action is needed.
- S:UScope, unchanged
- The dangling wiphy netns pointer is a kernel memory-safety bug inside the same kernel security authority. No VM or IOMMU boundary is crossed.
- C:HConfidentiality impact, high
- After the switch fails, rdev->wiphy keeps a pointer to a freed struct net from net_cachep. Later wiphy_net() users such as nl80211_notify_wiphy() and genlmsg_multicast_netns() dereference that freed object, a use-after-free that can be exploited for kernel memory disclosure.
- I:HIntegrity impact, high
- The freed struct net can be reallocated, for example by the attacker creating new namespaces. The stale wiphy then works on attacker-influenced net state, and this use-after-free of a core kernel object could be exploited for memory corruption.
- A:HAvailability impact, high
- syzbot hit a kernel fault in genlmsg_multicast_netns() via nl80211_notify_wiphy() in wiphy_unregister() when it touched the dangling netns pointer, which crashes the kernel.