CVE-2023-53822

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

wifi: ath11k: Ignore frags from uninitialized peer in dp.

When max virtual ap interfaces are configured in all the bands with ACS and hostapd restart is done every 60s, a crash is observed at random times. In this certain scenario, a fragmented packet is received for self peer, for which rx_tid and rx_frags are not initialized in datapath. While handling this fragment, crash is observed as the rx_frag list is uninitialised and when we walk in ath11k_dp_rx_h_sort_frags, skb null leads to exception.

To address this, before processing received fragments we check dp_setup_done flag is set to ensure that peer has completed its dp peer setup for fragment queue, else ignore processing the fragments.

Call trace: ath11k_dp_process_rx_err+0x550/0x1084 [ath11k] ath11k_dp_service_srng+0x70/0x370 [ath11k] 0xffffffc009693a04 __napi_poll+0x30/0xa4 net_rx_action+0x118/0x270 __do_softirq+0x10c/0x244 irq_exit+0x64/0xb4 __handle_domain_irq+0x88/0xac gic_handle_irq+0x74/0xbc el1_irq+0xf0/0x1c0 arch_cpu_idle+0x10/0x18 do_idle+0x104/0x248 cpu_startup_entry+0x20/0x64 rest_init+0xd0/0xdc arch_call_rest_init+0xc/0x14 start_kernel+0x480/0x4b8 Code: f9400281 f94066a2 91405021 b94a0023 (f9406401)

Tested-on: IPQ8074 hw2.0 AHB WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1

The issue in the ath11k driver allowed a NULL pointer dereference when fragmented Wi-Fi frames were received before datapath initialization for a peer. This could cause a kernel crash during packet processing. An attacker with local administrative access or control over the wireless interface (e.g., repeatedly restarting hostapd with multiple virtual APs) could trigger the race condition, leading to a denial of service (system crash).

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.