CVE-2024-47724 wifi: ath11k: use work queue to process beacon tx event
A bug in the ath11k WiFi driver causes a kernel crash when processing beacon transmission events, leading to a denial of service.
- 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-2024-47724?
CVE-2024-47724 is a high-severity denial of service vulnerability in Linux kernel, published on 21 Oct 2024. 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: ath11k: use work queue to process beacon tx event
Commit 3a415daa3e8b ("wifi: ath11k: add P2P IE in beacon template") from Feb 28, 2024 (linux-next), leads to the following Smatch static checker warning:
drivers/net/wireless/ath/ath11k/wmi.c:1742 ath11k_wmi_p2p_go_bcn_ie() warn: sleeping in atomic context
The reason is that ath11k_bcn_tx_status_event() will directly call might sleep function ath11k_wmi_cmd_send() during RCU read-side critical sections. The call trace is like:
ath11k_bcn_tx_status_event() -> rcu_read_lock() -> ath11k_mac_bcn_tx_event() -> ath11k_mac_setup_bcn_tmpl() …… -> ath11k_wmi_bcn_tmpl() -> ath11k_wmi_cmd_send() -> rcu_read_unlock()
Commit 886433a98425 ("ath11k: add support for BSS color change") added the ath11k_mac_bcn_tx_event(), commit 01e782c89108 ("ath11k: fix warning of RCU usage for ath11k_mac_get_arvif_by_vdev_id()") added the RCU lock to avoid warning but also introduced this BUG.
Use work queue to avoid directly calling ath11k_mac_bcn_tx_event() during RCU critical sections. No need to worry about the deletion of vif because cancel_work_sync() will drop the work if it doesn't start or block vif deletion until the running work is done.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30
Which versions are affected by CVE-2024-47724?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-47724?
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-2024-47724 being exploited?
There is no known exploitation of CVE-2024-47724 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-47724, DEBIAN-CVE-2024-47724, GHSA-g9m2-3h6c-58jq, UBUNTU-CVE-2024-47724.