CVE-2023-53822: 
Linux Kernel vulnerability analysis and mitigation

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