CVE-2023-53717

In the Linux kernel, the following vulnerability has been resolved:

wifi: ath9k: Fix potential stack-out-of-bounds write in ath9k_wmi_rsp_callback()

Fix a stack-out-of-bounds write that occurs in a WMI response callback function that is called after a timeout occurs in ath9k_wmi_cmd(). The callback writes to wmi->cmd_rsp_buf, a stack-allocated buffer that could no longer be valid when a timeout occurs. Set wmi->last_seq_id to 0 when a timeout occurred.

Found by a modified version of syzkaller.

BUG: KASAN: stack-out-of-bounds in ath9k_wmi_ctrl_rx Write of size 4 Call Trace: memcpy ath9k_wmi_ctrl_rx ath9k_htc_rx_msg ath9k_hif_usb_reg_in_cb __usb_hcd_giveback_urb usb_hcd_giveback_urb dummy_timer call_timer_fn run_timer_softirq __do_softirq irq_exit_rcu sysvec_apic_timer_interrupt

ath9k_wmi_cmd() could time out while a late WMI response still arrived and wrote into wmi->cmd_rsp_buf, which was a stack buffer no longer valid, causing a stack out-of-bounds write. The patch sets wmi->last_seq_id = 0 on timeout so late responses are discarded, preventing the write to a stale stack buffer. Primary impact is availability (kernel crash), with potential memory corruption in worst case. Triggering this issue typically requires local access with a connected AR9271 or ath9k_htc USB Wi-Fi dongle, along with the ability to induce command timeouts within the driver.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module ath9k_hw from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.