CVE-2026-80939 wifi: rtw89: pci: add .shutdown callback to stop rfkill polling on reboot
A missing shutdown callback in the rtw89 PCI driver causes kernel panics during warm reboot on arm64 platforms due to asynchronous SError interrupts.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-80939?
CVE-2026-80939 is a denial of service vulnerability in Linux, published on 11 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
wifi: rtw89: pci: add .shutdown callback to stop rfkill polling on reboot
Since the hardware rfkill polling was introduced, arm64 platforms can panic with an asynchronous SError during warm reboot:
SError Interrupt on CPU8, code 0x00000000be000011 -- SError Workqueue: events_power_efficient rfkill_poll [rfkill] rtw89_pci_ops_read8+0x94/0x160 [rtw89_pci] rtw89_core_rfkill_poll+0x50/0x1e0 [rtw89_core] rtw89_ops_rfkill_poll+0x40/0x68 [rtw89_core] ieee80211_rfkill_poll+0x3c/0x70 [mac80211] cfg80211_rfkill_poll+0x40/0x2a0 [cfg80211] rfkill_poll+0x30/0x88 [rfkill] Kernel panic - not syncing: Asynchronous SError Interrupt
On the reboot path the kernel only runs device_shutdown(), which calls each driver's .shutdown callback; .remove is not invoked. The rtw89 PCI driver had no .shutdown callback, so nothing stopped the rfkill polling work while the platform was tearing the PCIe link down. Once the link is gone, the next MMIO read from the poll handler targets a non-responding device and is reported as a fatal asynchronous SError on arm64.
Add rtw89_pci_shutdown(), wired to all rtw89 PCI device drivers, which sets a new RTW89_FLAG_SHUTDOWN flag (mirroring the USB RTW89_FLAG_UNPLUGGED pattern). When the flag is set, rtw89_ops_rfkill_poll() returns early, so no MMIO read is issued to the chip after shutdown begins and the SError no longer occurs.
This does not call the full .remove path from .shutdown, to keep the shutdown handler minimal and avoid running the non-idempotent teardown twice.
Which versions are affected by CVE-2026-80939?
How do I fix CVE-2026-80939?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-80939 being exploited?
There is no known exploitation of CVE-2026-80939 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-80939, DEBIAN-CVE-2026-80939, GHSA-q754-7p54-36jv, UBUNTU-CVE-2026-80939.